How can I stop people from hanging out at the empty house next door?

So the neighbors moved out last Labor Day and didn’t tell us that they lost the house. We know they did because the house has been sitting abandoned since. In that time, the wind and rain have knocked the gate to their backyard down. From then on, dogs and young kids have been going back there and frankly it has been driving me to distraction. Twice the gate has been put back up (not fixed) with the garbage cans in front. But the people who frequent there knock them down and leave the garbage lying around in the other yard. Is there any way I can prevent this from happening without having to go through red tape? Any ideas would be appreciated.