Definitely not that sophisticate yet. :)

It feels like we have to create a table of user -> marker locations to be able to deal with updates.  Can we get away with simply requerying the DB when the push notification comes?

```
User.getCurrentUser().findNearbyUsers(User.Type.VENDOR, new MarkerFactoryCallback(RequestVendorWaitActivity.this, map, SpeechBubble.ColorType.BLACK));
iconGenerator = new IconGenerator(RequestVendorWaitActivity.this);
User user = User.getCurrentUser();

MarkerFactoryCallback markerFactoryCallback = new MarkerFactoryCallback(iconGenerator, map, SpeechBubble.ColorType.BLACK) {
        @Override
        public void onError(Throwable e) {
                onError(e);
        }
};

user.getCurrentUser().findNearbyUsers(User.Type.VENDOR, markerFactoryCallback);

```