I have one of those no trespassing 2A signs on my front fence. Only the cable company debt collectors from previous tenants will venture past it.

They are immediately greeted with. "Ah, I can see because you have a list in front of you, that you can read. So why are you standing in front of my door where there was a no trespassing sign and gate you had to pass." They will then ask if some person is there,.. I will interrupt them mid sentence and ask "Do I need to get violent?" They leave immediately. The important thing is to talk clearly and calmly with no emotion, that is the scariest.