I have had someone arrested for standing when they should have been seated.
The problem with that is the Police processing the paperwork (UK). Also the courts seem to be very lenient these days when dealing with air safety issues.
I wouldn't do the emergency stop thing on purpose if they injured themselves I would quite rightly end up in court for it.
OK fair enough doing something deliberately may have consequences, but there are times when the Capt will brake hard for a reason and pax will fall over. I can't see anyone challenging that in court once the arrival announcements have been made. After all the cabin crew are also supposed to be remain seated whilst taxiing.