What would you do?

The neighborhood I live is going down hill. When we bought our house 5 years ago we fell in love with it because it had everything we wanted. The neighborhood is old and some of the houses are pretty run down but we knew we could deal with it because we only planned on being here for 5 years. Plus, our neighbors all around us were going to be great neighbors. All retired and had lived here for over 30 years. During the last several months someone has been spraying graffiti on fences and sidewalks and even garages. I can't even begin to explain how upset I am over it. I've been thinking that I should do something. Call a meeting and come together as a neighborhood to paint over and watch out for the jerks that are destroying property to mark their stupid territory. Yeah, its gang stuff. I never thought I would be living where something like this is going on. I feel like all the work that we have put into this house might have been a waste. What would you do? Would you try and be proactive, reclaim the neighborhood, or just leave as soon as you could? Our plans have always been to move around the 5th anniversary of the year we bought it, but we want to save up a little more so we can put 20% down on our next house. I don't know if I can wait. I feel so out of place here.