I guess I somehow haven't made myself clear, even though I explained everything in post #1, which does not indicate that I'm "always eyeing her kids".
The purpose is to let the owner of the house know what the tenants who are living in his house are doing, and that they are causing problems with neighbors through harassment, threats and property damage. He has the final say over who lives in his house and what is allowed to happen there. If what they're doing is going to give him a bad reputation as a landlord by allowing things to happen that causes the police to keep coming to his property, he will most likely have a talk with them, explaining that this behavior cannot continue or they will have to move out. The hoped for result is they start living more peacefully and allowing people around them to do the same, or they move to somewhere where their behavior is somehow acceptable.
If you were a landlord and had tenants that were causing problems for your neighbors, would you want to allow them to continue doing so? Unless someone were to inform you of what was happening, you'd have no way of knowing about it.