Unfortunately this is an incredibly difficult problem that's coming at us from every angle imaginable. The police don't enforce the noise ordinance (many police officers are Harley riders, btw), and the motorcycle riders change the exhaust on their bikes when it comes time for inspection.

This absolutely noise pollution and horribly annoying to not only pedestrians, but anyone within earshot of these obnoxious people. And don't buy their excuse that it's a safety issue and they want cars to hear them coming. Somehow bicyclists and electric cars fair just fine with minimal noise.

Police...shut these public nightmares down! Enforce the noise ordinance.