gistfile1.js

// Link service accounts when signed in
orig_updateOrCreateUserFromExternalService = Accounts.updateOrCreateUserFromExternalService;
Accounts.updateOrCreateUserFromExternalService = function(serviceName, serviceData, options) {
  var loggedInUser = Meteor.user();

  if (loggedInUser) {
    var setAttr = {};

    setAttr['linkedServices.' + serviceName] = serviceData;
    Meteor.users.update(loggedInUser._id, { $set: setAttr });
  }
};