Gangs
We live in a nice neighborhood, surrounded by nice neighborhoods. Across a major street is a small public housing project, which does not appear to be in disrepair. Every there's a high school a block away, and a large park 2 blocks away. Both of which are magnets for elements that would like to do something about these nice neighborhoods.
I've started seeing gang tagging on the sidewalks, buildings, and signage around the park. Gangs may be run by bullies in their 20s, but they prey on the not-so-swift high school kids who think they're tough. Tagging marks turf, and simultaneous tagging by rival gangs marks a war zone-to-be. Fortunately, Denver has a good graffiti removal program, which is about to get tested.