This is one of those things that suffers greatly from selection bias and language games. The people unbothered by minor impolite stuff don't come on the internet and complain. The people who think everyone going 5-over is a crisis do.

If you define dangerous as "how dare that BMW not use a blinker" type moves, yeah that stuff is everywhere.

If you define dangerous as "Y likely to cause an accident given X exposure" then it must be tautologically rare because if people were behaving seriously dangerously get bit by it in fairly short order. I can't remember the last time I saw a "wow, that was really pushing it and in poor taste" move. Weeks perhaps.