diff --git a/packages/accounts-facebook/facebook_server.js b/packages/accounts-facebook/facebook_server.js
index d457caab02..91eece0944 100644
--- a/packages/accounts-facebook/facebook_server.js
+++ b/packages/accounts-facebook/facebook_server.js
@@ -55,11 +55,7 @@
     }
 
     if (error_response) {
-      if (error_response.error) {
-        throw new Meteor.Error("Error trying to get access token from Facebook", error_response);
-      } else {
-        throw new Meteor.Error("Unexpected response when trying to get access token from Facebook", error_response);
-      }
+      throw new Meteor.Error(500, "Error trying to get access token from Facebook", error_response);
     } else {
       // Success!  Extract the facebook access token from the
       // response
@@ -72,7 +68,7 @@
       });
 
       if (!fbAccessToken)
-        throw new Meteor.Error("Couldn't find access token in HTTP response: " + response);
+        throw new Meteor.Error(500, "Couldn't find access token in HTTP response.");
       return fbAccessToken;
     }
   };
@@ -85,4 +81,4 @@
       throw result.error;
     return result.data;
   };
-}) ();
\ No newline at end of file
+}) ();
diff --git a/packages/accounts-oauth2-helper/oauth2_server.js b/packages/accounts-oauth2-helper/oauth2_server.js
index 1c083381b0..69a2b8941c 100644
--- a/packages/accounts-oauth2-helper/oauth2_server.js
+++ b/packages/accounts-oauth2-helper/oauth2_server.js
@@ -17,7 +17,7 @@
   //     - `null` if the user declined to give permissions
   Meteor.accounts.oauth2.registerService = function (name, handleOauthRequest) {
     if (Meteor.accounts.oauth2._services[name])
-      throw new Meteor.Error("Already registered the " + name + " OAuth2 service");
+      throw new Error("Already registered the " + name + " OAuth2 service");
 
     Meteor.accounts.oauth2._services[name] = {
       handleOauthRequest: handleOauthRequest
@@ -108,4 +108,4 @@
       }).run();
     });
 
-})();
\ No newline at end of file
+})();
diff --git a/packages/accounts-passwords/passwords_server.js b/packages/accounts-passwords/passwords_server.js
index 9335d3ffb1..4ecf87e8f1 100644
--- a/packages/accounts-passwords/passwords_server.js
+++ b/packages/accounts-passwords/passwords_server.js
@@ -9,9 +9,9 @@
 
   var selectorFromUserQuery = function (user) {
     if (!user)
-      throw new Meteor.Error("Must pass a user property in request");
+      throw new Meteor.Error(400, "Must pass a user property in request");
     if (_.keys(user).length !== 1)
-      throw new Meteor.Error("User property must have exactly one field");
+      throw new Meteor.Error(400, "User property must have exactly one field");
 
     var selector;
     if (user.id)
@@ -21,7 +21,7 @@
     else if (user.email)
       selector = {emails: user.email};
     else
-      throw new Meteor.Error("Must pass username, email, or id in request.user");
+      throw new Meteor.Error(400, "Must pass username, email, or id in request.user");
 
     return selector;
   };
@@ -39,11 +39,11 @@
 
       var user = Meteor.users.findOne(selector);
       if (!user)
-        throw new Meteor.Error("user not found");
+        throw new Meteor.Error(403, "user not found");
 
       if (!user.services || !user.services.password ||
           !user.services.password.srp)
-        throw new Meteor.Error("user has no password set");
+        throw new Meteor.Error(403, "user has no password set");
 
       var verifier = user.services.password.srp;
       var srp = new Meteor._srp.Server(verifier);
@@ -68,24 +68,24 @@
 
     changePassword: function (options) {
       if (!this.userId())
-        throw new Meteor.Error("must be logged in");
+        throw new Meteor.Error(401, "must be logged in");
 
       // If options.M is set, it means we went through a challenge with
       // the old password.
 
       // XXX && Meteor.accounts.config.unsafePasswordChanges check here!
       if (!options.M) {
-        throw new Meteor.Error("XXX no oldPassword unimplemented");
+        throw new Meteor.Error(500, "XXX no oldPassword unimplemented");
       }
 
       if (options.M) {
         var serialized = Meteor.accounts._srpChallenges.findOne(
           {M: options.M});
         if (!serialized)
-          throw new Meteor.Error("bad password");
+          throw new Meteor.Error(403, "bad password");
         if (serialized.userId !== this.userId())
           // No monkey business!
-          throw new Meteor.Error("bad password");
+          throw new Meteor.Error(403, "bad password");
       }
 
       var verifier = options.srp;
@@ -94,7 +94,7 @@
       }
       if (!verifier || !verifier.identity || !verifier.salt ||
           !verifier.verifier)
-        throw new Meteor.Error("Invalid verifier");
+        throw new Meteor.Error(400, "Invalid verifier");
 
       Meteor.users.update({_id: this.userId()},
                           {$set: {'services.password.srp': verifier}});
@@ -146,12 +146,12 @@
     if (!options.srp)
       return undefined; // don't handle
     if (!options.srp.M)
-      throw new Meteor.Error("must pass M in options.srp");
+      throw new Meteor.Error(400, "must pass M in options.srp");
 
     var serialized = Meteor.accounts._srpChallenges.findOne(
       {M: options.srp.M});
     if (!serialized)
-      throw new Meteor.Error("bad password");
+      throw new Meteor.Error(403, "bad password");
 
     var userId = serialized.userId;
     var loginToken = Meteor.accounts._loginTokens.insert({userId: userId});
@@ -180,11 +180,11 @@
     var selector = selectorFromUserQuery(options.user);
     var user = Meteor.users.findOne(selector);
     if (!user)
-      throw new Meteor.Error("user not found");
+      throw new Meteor.Error(403, "user not found");
 
     if (!user.services || !user.services.password ||
         !user.services.password.srp)
-      throw new Meteor.Error("user has no password set");
+      throw new Meteor.Error(403, "user has no password set");
 
     // Just check the verifier output when the same identity and salt
     // are passed. Don't bother with a full exchange.
@@ -193,7 +193,7 @@
       identity: verifier.identity, salt: verifier.salt});
 
     if (verifier.verifier !== newVerifier.verifier)
-      throw new Meteor.Error("bad password");
+      throw new Meteor.Error(403, "bad password");
 
     var loginToken = Meteor.accounts._loginTokens.insert({userId: user._id});
     return {token: loginToken, id: user._id};
diff --git a/packages/accounts/accounts_server.js b/packages/accounts/accounts_server.js
index 2f0830c78d..e13e9ebeb7 100644
--- a/packages/accounts/accounts_server.js
+++ b/packages/accounts/accounts_server.js
@@ -40,7 +40,7 @@
     });
 
     if (result === undefined) {
-      throw new Meteor.Error("Unrecognized options for login request");
+      throw new Meteor.Error(400, "Unrecognized options for login request");
     } else {
       return result;
     }
@@ -61,7 +61,7 @@
       var loginToken = Meteor.accounts._loginTokens
             .findOne({_id: options.resume});
       if (!loginToken)
-        throw new Meteor.Error("Couldn't find login token");
+        throw new Meteor.Error(403, "Couldn't find login token");
 
       return {
         token: loginToken._id,
diff --git a/packages/mongo-livedata/allow_tests.js b/packages/mongo-livedata/allow_tests.js
index c03542e23b..7d725c7d9e 100644
--- a/packages/mongo-livedata/allow_tests.js
+++ b/packages/mongo-livedata/allow_tests.js
@@ -108,12 +108,12 @@
       update: function(userId, docs) {
         // throw fields in first doc so that we can inspect them in test
         throw new Meteor.Error(
-          "Test: Fields in doc: " + _.keys(docs[0]).join(','));
+          999, "Test: Fields in doc: " + _.keys(docs[0]).join(','));
       },
       remove: function(userId, docs) {
         // throw fields in first doc so that we can inspect them in test
         throw new Meteor.Error(
-          "Test: Fields in doc: " + _.keys(docs[0]).join(','));
+          999, "Test: Fields in doc: " + _.keys(docs[0]).join(','));
       },
       fetch: ['field1']
     });
@@ -128,12 +128,12 @@
       update: function(userId, docs) {
         // throw fields in first doc so that we can inspect them in test
         throw new Meteor.Error(
-          "Test: Fields in doc: " + _.keys(docs[0]).join(','));
+          999, "Test: Fields in doc: " + _.keys(docs[0]).join(','));
       },
       remove: function(userId, docs) {
         // throw fields in first doc so that we can inspect them in test
         throw new Meteor.Error(
-          "Test: Fields in doc: " + _.keys(docs[0]).join(','));
+          999, "Test: Fields in doc: " + _.keys(docs[0]).join(','));
       },
       fetch: ['field1']
     });
@@ -160,7 +160,7 @@
       function (test, expect) {
         restrictedCollectionForPartialAllowTest.update(
           {world: test.runId()}, {$set: {updated: true}}, expect(function (err, res) {
-            test.equal(err.error, 'Access denied. No update validators set on restricted collection.');
+            test.equal(err.error, 403);
           }));
       }
     ]);
@@ -177,22 +177,22 @@
         restrictedCollectionForFetchTest.update(
           {world: test.runId()},
           {$set: {updated: true}}, expect(function (err, res) {
-            test.equal(err.error, "Test: Fields in doc: field1,field2,_id");
+            test.equal(err.reason, "Test: Fields in doc: field1,field2,_id");
           }));
         restrictedCollectionForFetchTest.remove(
           {world: test.runId()}, expect(function (err, res) {
-            test.equal(err.error, "Test: Fields in doc: field1,field2,_id");
+            test.equal(err.reason, "Test: Fields in doc: field1,field2,_id");
           }));
 
         restrictedCollectionForFetchAllTest.update(
           {world: test.runId()},
           {$set: {updated: true}}, expect(function (err, res) {
-            test.equal(err.error,
+            test.equal(err.reason,
                        "Test: Fields in doc: field1,field2,field3,world,_id");
           }));
         restrictedCollectionForFetchAllTest.remove(
           {world: test.runId()}, expect(function (err, res) {
-            test.equal(err.error,
+            test.equal(err.reason,
                        "Test: Fields in doc: field1,field2,field3,world,_id");
           }));
 
@@ -225,7 +225,7 @@
       },
       function (test, expect) {
         lockedDownCollection.insert({world: test.runId(), foo: 'bar'}, expect(function (err, res) {
-          test.equal(err.error, "Access denied");
+          test.equal(err.error, 403);
         }));
         Meteor.default_connection.onQuiesce(expect(function () {
           test.equal(lockedDownCollection.find({world: test.runId()}).count(), 0);
@@ -290,14 +290,14 @@
           // insert checks validator
           function (test, expect) {
             collection.insert({world: test.runId(), canInsert: false}, expect(function (err, res) {
-              test.equal(err.error, "Access denied");
+              test.equal(err.error, 403);
               test.equal(collection.find({world: test.runId()}).count(), 0);
             }));
           },
           // insert checks all validators
           function (test, expect) {
             collection.insert({world: test.runId(), canInsert: true}, expect(function (err, res) {
-              test.equal(err.error, "Access denied");
+              test.equal(err.error, 403);
               test.equal(collection.find({world: test.runId()}).count(), 0);
             }));
           },
@@ -343,9 +343,7 @@
               {canInsert: true, world: test.runId()},
               {newObject: 1},
               expect(function (err, res) {
-                test.equal(
-                  err.error,
-                  "Access denied. Can't replace document in restricted collection.");
+                test.equal(err.error, 403);
               }));
           },
 
@@ -363,7 +361,7 @@
               {world: test.runId(), canInsert: true, canUpdate: true},
               {$set: {"verySecret.field": 1}},
               expect(function (err, res) {
-                test.equal(err.error, "Access denied");
+                test.equal(err.error, 403);
               }));
           },
 
@@ -382,7 +380,7 @@
           // update fails when access is denied trying to set `verySecret`
           function (test, expect) {
             collection.update({world: test.runId(), canInsert: true}, {$set: {verySecret: true}}, expect(function (err, res) {
-              test.equal(err.error, "Access denied");
+              test.equal(err.error, 403);
               // nothing has changed
               test.equal(collection.find({world: test.runId()}).count(), 3);
               test.equal(collection.find({world: test.runId()}).fetch()[1].canInsert, true);
@@ -394,7 +392,7 @@
           // `verySecret`
           function (test, expect) {
             collection.update({world: test.runId(), canInsert: true}, {$set: {updated: true, verySecret: true}}, expect(function (err, res) {
-              test.equal(err.error, "Access denied");
+              test.equal(err.error, 403);
               // nothing has changed
               test.equal(collection.find({world: test.runId()}).count(), 3);
               test.equal(collection.find({world: test.runId()}).fetch()[1].canInsert, true);
@@ -406,7 +404,7 @@
           // have `canUpdate` set
           function (test, expect) {
             collection.update({world: test.runId(), canInsert: true}, {$set: {updated: true}}, expect(function (err, res) {
-              test.equal(err.error, "Access denied");
+              test.equal(err.error, 403);
               // nothing has changed
               test.equal(collection.find({world: test.runId()}).count(), 3);
               test.equal(collection.find({world: test.runId()}).fetch()[1].canInsert, true);
@@ -426,7 +424,7 @@
           // `canRemove` set
           function (test, expect) {
             collection.remove({world: test.runId(), canInsert: true}, expect(function (err, res) {
-              test.equal(err.error, "Access denied");
+              test.equal(err.error, 403);
               // nothing has changed
               test.equal(collection.find({world: test.runId()}).count(), 3);
             }));
@@ -434,7 +432,7 @@
           // another test that remove fails with no `canRemove` set
           function (test, expect) {
             collection.remove({world: test.runId(), canUpdate: true}, expect(function (err, res) {
-              test.equal(err.error, "Access denied");
+              test.equal(err.error, 403);
               // nothing has changed
               test.equal(collection.find({world: test.runId()}).count(), 3);
             }));
diff --git a/packages/mongo-livedata/collection.js b/packages/mongo-livedata/collection.js
index 00c773e212..6de43b483d 100644
--- a/packages/mongo-livedata/collection.js
+++ b/packages/mongo-livedata/collection.js
@@ -153,10 +153,10 @@ Meteor.Collection.prototype._defineMutationMethods = function() {
       if (!this.is_simulation) {
         if (self._restricted) {
           if (!self._allowInsert(this.userId(), doc))
-            throw new Meteor.Error("Access denied");
+            throw new Meteor.Error(403, "Access denied");
         } else {
           if (!insecure)
-            throw new Meteor.Error("Access denied");
+            throw new Meteor.Error(403, "Access denied");
         }
       }
 
@@ -178,7 +178,7 @@ Meteor.Collection.prototype._defineMutationMethods = function() {
             // update returns nothing.  allow exceptions to propagate.
             self._collection.update(selector, mutator, options);
           } else {
-            throw new Meteor.Error("Access denied");
+            throw new Meteor.Error(403, "Access denied");
           }
         }
       }
@@ -198,7 +198,7 @@ Meteor.Collection.prototype._defineMutationMethods = function() {
             // insert returns nothing.  allow exceptions to propagate.
             self._collection.remove(selector);
           } else {
-            throw new Meteor.Error("Access denied");
+            throw new Meteor.Error(403, "Access denied");
           }
         }
       }
@@ -249,7 +249,7 @@ Meteor.Collection.prototype.allow = function(options) {
 // assuming the collection is restricted
 Meteor.Collection.prototype._allowInsert = function(userId, doc) {
   if (this._validators.insert.length === 0) {
-    throw new Meteor.Error("Accesd denied. No insert validators set on restricted collection.");
+    throw new Meteor.Error(403, "Access denied. No insert validators set on restricted collection.");
   }
 
   // all validators should return true
@@ -266,14 +266,14 @@ Meteor.Collection.prototype._validatedUpdate = function(userId, selector, mutato
   var self = this;
 
   if (self._validators.update.length === 0) {
-    throw new Meteor.Error("Access denied. No update validators set on restricted collection.");
+    throw new Meteor.Error(403, "Access denied. No update validators set on restricted collection.");
   }
 
   // compute modified fields
   var fields = [];
   _.each(mutator, function (params, op) {
     if (op[0] !== '$') {
-      throw new Meteor.Error("Access denied. Can't replace document in restricted collection.");
+      throw new Meteor.Error(403, "Access denied. Can't replace document in restricted collection.");
     } else {
       _.each(_.keys(params), function (field) {
         // treat dotted fields as if they are replacing their
@@ -310,7 +310,7 @@ Meteor.Collection.prototype._validatedUpdate = function(userId, selector, mutato
   if (_.any(self._validators.update, function(validator) {
     return !validator(userId, docs, fields, mutator);
   })) {
-    throw new Meteor.Error("Access denied");
+    throw new Meteor.Error(403, "Access denied");
   }
 
   // construct new $in selector to replace the original one
@@ -333,7 +333,7 @@ Meteor.Collection.prototype._validatedRemove = function(userId, selector) {
   var self = this;
 
   if (self._validators.remove.length === 0) {
-    throw new Meteor.Error("Access denied. No remove validators set on restricted collection.");
+    throw new Meteor.Error(403, "Access denied. No remove validators set on restricted collection.");
   }
 
   var findOptions = {};
@@ -350,7 +350,7 @@ Meteor.Collection.prototype._validatedRemove = function(userId, selector) {
   if (_.any(self._validators.remove, function(validator) {
     return !validator(userId, docs);
   })) {
-    throw new Meteor.Error("Access denied");
+    throw new Meteor.Error(403, "Access denied");
   }
 
   // construct new $in selector to replace the original one