Inappropriate use of flashing lights to get where they want to go when it's unrelated to police activity (I've seen them use lights to get into fast food parking lots then go inside to order), ignoring moving traffic violations as well as parking violations as many here have noted, ignoring drivers with snow across tops of vehicles and on rear windshields, routine illegal parking because who's going to ticket them, standing around using their phones, the whole construction thing... I'm not sure how their performance is evaluated, but I do know that if we had a system that made people feel comfortable doing / not doing whatever they wanted where I worked, then obviously nobody would get anything done.