Facebook will typically lock such accounts until you give him pictures of yourself in your house with your driver's license.
I also know someone who wanted to change their last name (their current one is already fake) and the system didn't let them without sending an ID.
[0] https://www.facebook.com/help/community/question/?id=1016165...
We made a Facebook account for Marcelo a few years back as a joke. One day a couple years in, we could no longer log into his account without proving his identity. We probably tripped some internal flags because it was being logged into by several IPs that also had their own Facebook accounts is my guess, that or someone not in on the joke reported Marcelo. Either way, Marcelo can't use Facebook anymore... A small inconvenience in our case, but this is definitely something that can and does happen to fake accounts.
Annoyingly, someone/somebot made a full mirror of my Facebook account one day and sent me a friend request as well as several of my friends and family. I reported it and eventually got back a response that the account was not in violation of any rules. That was years ago and I had forgotten about it until just now. Just checked today and it seems it's actually gone, but it was very creepy at the time.
It was probably two months before my account was flagged for "suspicious activity" and asked that I submit a photo of a government-issued ID, which I never obliged.
However, now the create a new account page says there’s an existing disabled account with this email address, but the account support portal says one doesn’t exist! Top notch engineering. Luckily I have my IG account for Messenger login, but I can’t use it for desktop sign-on’s which is pretty dumb.