A very friend of mine was going through a nasty divorce. Although we weren't talking about the divorce/case he set our messages on auto-delete. Apparently his (now, ex-wife) had SMS and WhatsApp messages in court to be used for her cased.

Any 'loving message' to her from the early days ("you are so perfect") and any 'nasty message' to others ("oh that bitch!!") sent to anyone was presented in court. So for caution he auto-deleted even the messages that were innocuous, just in case it could be used against him "oh he wanted to spend money for a new phone/laptop, thus he has money, thus I will take it"