Including Google. There was a well-publicized case in which they were "hoist on their own petard" a few years back.
What happened, basically, from memory, is that someone was arguing that Google did something wrong (I forget, but it might have been the collusion to keep down employee wages or something) and so there was discovery of emails by Google, and they eat their own dogfood so it was gmail.
So Google smugly said "hah, there aren't any incriminating emails", but then it turned out that the autosaved drafts of some of their emails were incriminating, and were preserved, and ended up being produced in court.
So remember that the next time you type an email or a forum or facebook post, and you revise it extensively before hitting the button to send it.
Well, after...Googling...it, there's a little more to the story. It was actually a fight with Oracle about the usual stuff (Java patents), and the email itself was covered by attorney-client privilege, and therefore didn't have to be shown to the other side, but the drafts slipped through by accident because, you know, the subject didn't actually say "Attorney work product - confidential" until almost the final version. And although there is something called a "clawback", the judge ruled that their attempt was too little and too late. "Your honor, it's devastating to my case!"
Basically, Google relied on an algorithm/search engine to screen for privileged documents instead of having lawyers review things the old-fashioned way and they got bit by that.
What happened, basically, from memory, is that someone was arguing that Google did something wrong (I forget, but it might have been the collusion to keep down employee wages or something) and so there was discovery of emails by Google, and they eat their own dogfood so it was gmail.
So Google smugly said "hah, there aren't any incriminating emails", but then it turned out that the autosaved drafts of some of their emails were incriminating, and were preserved, and ended up being produced in court.
So remember that the next time you type an email or a forum or facebook post, and you revise it extensively before hitting the button to send it.