Everyone has pet peeves. For members of the media like myself, most of the times it's bad grammar. Not knowing the difference between your and you're is just one example. Others might be irritated by not knowing the difference between loose and lose, or between affect and effect.
Sure, the English language can be confusing at times. Take it from me, I communicate for a living! It takes a lot of hard work to master vocabulary, syntax and grammar. And not everyone is perfect.
But one man has taken his hatred of bad grammar to the extreme by making more than 47,000 edits to Wikipedia.