I just noticed an oddity earlier today: Despite a question being moved from StackOverflow to Meta, I could still vote for answers on the original question on SO.
Shouldn't voting be locked on migrated questions?
The answers themselves should have been deleted, locked to prevent undeletion, and new answers prohibited by the closing of the question itself.
Unfortunately, there are several features of the system for closing and deleting posts that make it possible - and fairly common - for answers to persist on migrated questions. IMHO, the system needs to be changed to lock down migrated questions more rigidly than other sorts of closed/locked questions.