Always a problem. No perfect solutions.

Can't shoot, because bylaws prohibit discharge of firearms in the city. Surveillance cameras infringe on privacy bylaws. Bylaws prohibit cats and dogs from leaving the owner's property without restraints, but wandering animals are long gone by the time bylaw-enforcement people arrive. Poison candy in the flower beds would eliminate stray animals and children, but solutions of that sort are frowned on. Fencing limited to 3-4 feet here; easily vaulted. If water restrictions are on, hosing someone could get you fined.
Poison ivy and nettles could be added to plantings, but weed bylaws would result in fines. Keeping a junkyard dog is against bylaws unless there is a secure fence (which hides your plantings).

I remember a woman in Texas who had a sign in her front yard- Grass infested with chiggers! Won't work here because we don't have them.