Agreed, there are serious issues if the sender and receiver don't coordinate. The feature already exists with only minimal DIY though. An alternative implement

Agreed, there are serious issues if the sender and receiver don't coordinate. The feature already exists with only minimal DIY though. An alternative implementation would have to contend with the same social issue. The easiest solution to the social coordination issue I'm aware of is the second option I mentioned. Hand out a unique address that you whitelist. Possibly burn it later if necessary.