I was wondering whether this is actually the same as like jacking. Is the ‘leak’ in that case the ability for the Facebook page/post owner to be able to then look you up in the list of ‘likes’? If so, I think Facebook privacy settings may allow users to not leak their emails or pictures in this case.

Also, I think it’s more widespread given that ‘Google identity’ covers a large number of Google products, and signing into one signs into all. With Facebook any time I log in nowadays I open incognito, check messages, log out, whereas with Google I generally stay logged in, mostly because I want gmail and my cross device browsing history to work.