I have heard stories from 3 of my teachers about how at their old schools large amounts ("nearly all" of one GPS school) of kids accessed special provisions to get extra time and such even if they didn't need it, it doesn't happen at my school so I can't say I've seen it 1st hand but I personally believe the system is frequently exploited.
Some of the ones I have heard of are a joke, like extra time for 'sore hands' and such, I did my SC with a fractured thumb AND a boxer's fracture (5th metacarpal), both on my writing hand and I didn't ask for extra time or anything, just took a few painkillers and removed my splints for the exam. I think people that deserve provisions should most definitely get them, the rest should not.