It would probably be difficult to prove with certainty, but depending on what the passwords are, you could potentially be able to do something like that. For ex

It would probably be difficult to prove with certainty, but depending on what the passwords are, you could potentially be able to do something like that. For example, if there are enough accounts that have the same password (which is also relatively unique), then at some point it will be a statistical impossibility that they were all created by different people.