code: function clientSubscribe(loc, cb) {
    fayeClient.subscribe(loc, function(data) {
      var user = GLOBAL.svc.auth.userByClientID(data.clientID), clientID;
      if (user) {
        clientID = data.clientID;
        delete data.clientID;
        cb(data, clientID, user.username);
      } else {
        GLOBAL.error(loc, 'invalid client', clientID, 'data', data);
        publish('/loggedOut', {}, clientID);
      }
    });
  }
docs: Validates client subscriptions against session / system IDs.