At the high school I went to, lately they have been installing special "stopper" covers over the pull stations for the fire alarm. They are designed so when the cover is lifted, it makes a loud beeping sound, which would either ward off potential pranksters, or cause nearby people to come running, and if it's a prankster catch them in the process. They began installing them due to the high frequency of false fire alarms, though they still have a pretty crappy fire alarm panel. Good thing the alarms didn't go off there today, as they are still the loudest in my city!