In California you are not legally allowed to audio record someone in private without their consent. They must know that they are being recorded for it to be used as evidence in court.
Here it is:
You seem obsessed with laws, as if they possess value and worth in and of themselves, when really they are a very high latency sidechannel of society and power.
https://news.ycombinator.com/item?id=6033481
It's probably a bit too sharp a response to your comment, but it certainly get's the point across.
The point is to take things public.
The court of public opinion is a hugely effective weapon, if you have the documented evidence to back it up.
And if they threaten you about wiretapping laws or whatever, well that just makes the company look even worse in the court of public opinion.
If you will notice, nobody at Uber was stupid enough to threaten Susan Fowler for documenting the stuff that happened to her.