The phrase "check yourself before you wreck yourself" actually is quite accurate, especially when it comes to situations like these. When you're trying to make a point, debunk something or just criticize something online, it is important to remember just how public everything is. On sites like Twitter, everyone has an account, including most celebrities and other big names and professionals. Twitter makes it easy to see when someone mentions them too. So if you say something about someone online, chances are they will see it, and might even respond to it, especially if it isn't true.

This is an embarrassing thing to watch go down, especially with someone who is so confident in what they're saying being shot down by a person who genuinely and definitely knows more than them. It is just something most people want to avoid. Reddit's /r/dontyouknowwhoiam features accounts of people saying things online without realizing they are talking to the person it is about. Sometimes it is just funny, other times it is really cringeworthy. For some serious secondhand embarrassment, here are 15 people who didn't realize who they were talking to.