Once five Hispanics and/or three Muslims made the banned list, they’d sue and BART would cave faster than you could say “profiling”.
But, who is going to ENFORCE the ban on criminal riders? the subway drivers? Other passengers? Perhaps illegal immigrants from El Salvador? Maybe they could hire the Bloods on some lines, and the Crips on other routes?
If you want to fix fare cheats...require everyone to use a standard chip-card that the train system utilizes. Once they commit some fare issue or crime...you should absolutely lock them out for six months. If they show back up in the system with a loaner chip-card from a buddy...toss the buddy for six months as well. Within a year or two...you’d end fare cheats and motivate people to act like they should.
It is odd that they could not send a Persona Non Grata letter to disorderly people. It could be they that they didn’t pay the lawmakers the required bribes.