Rogers Park- are police afraid to patrol?

In case you missed it, after yesterday's Memorial Day parade wrapped up there was an hours long, glass shaking "let's see how loud it can get" contest next to the children's playground in Rogers Park between a few individuals who proudly showed off their 3ft-5ft stacks of car speakers. There is a small "No Loud Music" sign posted about 100ft away, conveniently misplaced on the end of a set of bleachers, readable from one direction only. Yes, I know it was a holiday. It was most people's holiday. I can only imagine how many family picnics, baby naps and pet's sanity got disturbed by this performance. The most bothersome part is the lack of police patrols in the park. Every single day there are moms in minivans speeding to school or baseball practice, loud thumping car radios, drag racing/ peeling out, cruising back and forth in the cars/motorcycles with crazy exhaust pipes and parents who don't secure their kids in seat belts. I have my theories of why the DPD is apprehensive about showing themselves that often in the park, but the law is the law and it's getting out of control.