Facebook is already strict enough and doesn't need detection algorithms like this. I once setup an array of doppelgänger accounts to see how long it would take

Facebook is already strict enough and doesn't need detection algorithms like this. I once setup an array of doppelgänger accounts to see how long it would take for Facebook to correlate the accounts and ban all those accounts in one fell swoop. It was not long until each account was subjected to a rigorous test, where I was asked to match people's Facebook photos with their username. A daunting task if most of your friends were token friends added merely to boost your profile and make it seem popular. Of course I managed to solve half of those prompts, but the other doppelgänger accounts were swiftly banned, leading me to think that Facebook's algorithm works half the time, which in computer science terms is not good enough, but in reality, is enough to deter a substantial amount of bad actors.