Yeah I wouldn't say "normal" (how should we quantify that?), but they do exist. Most engineers at Google, Facebook, etc. don't pass the senior level, and that's the last engineering rung everyone is expected to at least achieve.

But if you do know staff or senior staff engineers at Google and Facebook working in NYC or SF, it is disproportionately likely that they are earning in excess of $300k/year between salary, bonus and stock grants. I know people like that directly, and I also know undergrads who are receiving between $120-$150k/year in coastal cities in total compensation offers amortized over four years.

People probably aren't lying on Hacker News, the medium just lends itself to reporting bias. Large forums like this have enough participants that I'm not really surprised when 10 or so people come into a thread and claim to earn something like half a million per year. It looks outlandish but there is a vast swath of engineers who are just not speaking up; for the distribution, it's probably about right. It's not as if people are claiming these salaries as base compensation before bonus and stock.