Our condominium complex has three metal gate doors with closing springs and regular door latches (with medico keys, of course). We keep having problems with a couple renters and hoods from the neighborhood filling the catches with rocks so that the doors don't shut all the way, or propping the gates open with rocks (because they don't feel like paying the $25 fee for a key). We've had two robberies, one where someone came in the one unlatched gate, cut our driveway gate opener chain with a bolt cutter, drove his van in and stole a resident's scooter. (we actually have video of him on our motion sensor cameras which we turned over to police). Have other condo complexes had this problem? How did you deal with it? Is there any kind of device or different kind of locks we can install on the gate that are tamper-proof (maybe locks that don't have a recessed hole/catch that someone can fill with stones)?