The "Black List" you all speak of has a lot to do with whatever internal programs an area say, like Guest Relations uses to keep track of Guests electronically. I know WDW has this but not sure if SDC does. This isn't to say even in this case that the park has any wherewithal to keep tabs on their return.
Now, if WDW ever calls in Law Enforcement (in guest-to-guest or guest-to-employee altercations), then a BOLO will be sent across property. This is done sometimes with those scamming tickets or carrying counterfeit money. In this case, there IS a master list of "black listed" people.
But as it was mentioned before, the parks themselves and the people who operate them are just that....people and cannot be everywhere at once. If a park executive makes an official "don't come back" remark to someone though, you had better believe that this will be recorded electronically somewhere and will most likely never be expunged.
