I seriously doubt they actually enforce the ban, I've know too many people that were given "life time bans" from places that will end up back within months and in one case even got a job where they were banned. Not saying you wouldn't have to wait a while, but I seriously doubt they would do anything other than have you name on a list that wouldn't be allowed to buy APs or things that would clearly be stored in their computer. Given they only take a few points on your finger and are trying to make sure that someone's finger is close to the original scanned finger I would expect their system is limited in the actual number of different prints it has on file and would not be surprised if numerous people had the same coded print on file, but the number is just so large that the odds of you using someone else's ticket and having the same print are very small.... Given the FBI's own internal report said their system gave false matches 10% of the time I can't see Disney having a better system. As for photographs, I'm sure they have them of people that are banned, probably even keep them, but I don't think they are going to install the equipment in the parks to actually do facial recognition of every guest in the park it would be very expensive, have limited value and once the public found out (which they would) would be a PR nightmare when some privacy groups got word.
In the end I expect they ban the person, tell them they will be charged with trespassing if they show up again, and don't do much beyond that expecting the paranoia and fear to keep the person from returning.
In the end I expect they ban the person, tell them they will be charged with trespassing if they show up again, and don't do much beyond that expecting the paranoia and fear to keep the person from returning.