Paintball guns are not exactly quiet and don't have sufficient range to even allow you to stand outside the parking lot of most Federal buildings and still reach them, let alone outside of the purview of their security cameras. When you're caught you'll inevitably be holding a Gun Shaped Object, which is unlikely to go down well. I admire the spirit, but I'd advise you to think about that one a smidge harder, if I were you.

If you're going to sabotage, then sabotage. Don't go for middle school level vandalism pranks.