When applying to big tech companies(FAANG or similar, or even smaller multibillion dollar companies), would they check any accounts and the private data you may have on personal accounts on their platform when you apply or interview with them?(for example emails account at gmail or outlook, social media accounts private data, LLMs conversations etc...)

As some kind of additional background check.

Is this something that a recruiter may be able to do during, before or after some hiring process?

My gut feeling is that it wouldn't be legal in most places, but do some of them do it anyway?

Has any of you been part of hiring decisions at those type of companies and saw it happen or did it yourselves?