The motorcycling community has this stupid mantra "loud pipes save lives." There's only one problem: it isn't true. There is no compelling evidence backing up that claim. They then use it as an excuse to get the most obnoxiously loud pipes they can - often illegally modifying them to remove baffles so they can be even louder! I have no idea why this isn't being policed as it's easy to do.
Their bikes are so damned loud I can't even ride alongside of them. The one thing that gives me a smile is I know in 20-30 years they are going to have one helluva case of tinnitus. Yeah, payback really is a bitch!
You could also just wish that their bike gets crushed and that they loose their licence. Or maybe that they get an itch they just can't quite reach.