I'm fairly certain the corporate guys at my old airport would intentionally set off RAs to PIT arrivals. Our departures climbed to 3000 while the PIT arrivals went over the departure path at 4. I swear the traffic call I'd make triggered a "let's see if we can set off that guy's TCAS." Saw it happen more than once. Had to do with the climb rate of the departure. I'd see the arrival start climbing while the departure still had well over 1000 ft of separation.