I work in Law Enforcement and did Security for quite a few years (not WDW) and this is pretty much how it works. If someone is really bad, they might post their pictures for employees to see, etc. That would be for fraud related issues, but your normal people banned are given trespass warnings and than if they are every caught and their names checked in the WDW database of banned persons, they can charge them, even if they didn't steal something or whatever. Employee recognition is big too, many employees will remember people they encounter that were stealing, etc and call security when the person comes back. This is especially true for locals that might frequent WDW. As far as the face scanning, yes they are out there, but they are very costly and it isn't worth the expense to run those systems for minor issues. Some of the best Casinos use them to help prevent losses from cheaters, but most casinos will not use them because they are so expensive and just really aren't the most effective use of resources (each face of every patron being run, etc). You have to be careful what is on tv, most show exaggerate the truth of how technology is being used. CSI is the best example, prosecutors are having serious problems with juries that expect all the evidence to be done like it is in CSI, which just doesn't happen.