Lots of terrible content is posted on the internet every day. Whether it’s because they’ve realized what terrible things they’ve said, or they want to pretend it doesn’t exist, they delete it. Between posting and deleting, people tend to take screenshots of the offending content. Problem is, you should never trust screenshots&emdash;they’re too easy to fake.
A solution to this would just be to archive offending content on the Wayback Machine. It keeps a pure and unadulterated history of things. Sure, it isn’t perfect since it can be blocked from archiving, and they honor copyright requests, but it’s a pretty good receipt log.