If it gets so bad that a society/academic system needs to criminalize such fraud, they have already lost that race.
The only thing that really works is a culture where this rarely if ever happens, because of the peer respect and self-respect of academics.
Do you know a trick to pay my bills in self-respect? Most of my creditors demand I pay in money.
Edit: For some reason this account has been restricted. Goodbye HN, see you on the next sockpuppet. I wasn't expecting an account named after a racial slur to last so long.