.
If they do have a source, then that's something that we'll need to detect. The merit transfers are public, so it shouldn't be that difficult. There are also various limits in place which would help to limit the damage from that.
Will something like a trust feedback for merit be added? It would be an enormous hassle to look through individual posts to see who gave who merit. ( Even with the sort of whitelist for sources)
Abuse would be much easier to see aswell.