Waivers and or NDAs- how common are these? USA mainly

Hi all, was wondering about things and looked back at some possible plans which Covid also got in the way of.

Saw Waivers mentioned and as I understand it these can impart an obligation of confidence.

What sort of penalty clauses are typically in these- thinking from a Bustee perspective, if he went blabbing on Twitter how much might he stand to be sued for? I am a bit surprised about the confidentiality aspect. There if I do a session and one arises would be one way to find out. ;)

Cheers...