After every contest, the ratings should not increase immediately. A projected increase should be shown instead. Final ratings should be updated once the plag checkers have run their course.
I am aware that this is a crude solution and I’m sure someone has thought of this before, why has it not been implemented (In some form) yet? People would be happy to wait for a few weeks for their ratings to solidify, if they haven’t cheated, then their ratings would only be higher than the projected ratings. The key here is to give a temporary name to the increased ratings until they are confirmed.
We can’t stop people from uploading the answers( Reporting? lol), we can only stop people from trying to copy.