It seems like these days, the most popular way to prove how smart you are online is by correcting other people's grammar and spelling. I see it everyday - someone is always pointing out how another person used the wrong their/there/they're or your/you're. Don't make any mistakes online; there is always someone who can't wait to correct you.
I always ask what purpose they're trying to serve. What does that correction add to the conversation? Could you understand what they meant to say in the first place? Yes? Then what are you trying to accomplish?
The only thing I can come up with is that they're tying to show how smart they are. "Look at me! I noticed you made a mistake and I'm going to show you how smart I am by pointing out how dumb you are!"
It hardly ever adds anything to the conversation, and I'm pretty sure you can almost always tell what they really meant. I would argue that a lot of these mistakes are just that - mistakes. People aren't dumb for mixing up you're and your in their facebook status update. I like to believe that even if it isn't spelled right, you probably knew what they were trying to say and your correction does nothing to further the conversation.
It especially bugs me a lot when someone with more education points out a mistake someone less educated made. It really seems like someone picking on another person who hasn't been as fortunate as them. We get it, you have a university degree. Who are you trying to impress? Why are you still trying to prove how smart you are. Why are you picking on someone who doesn't have the same background? Not everyone learns advanced English in Highschool... Grammar and spelling mistakes are the low hanging fruit. Why not add something useful to the conversation?
A friend of mine misspelled a tweet and had over 20 people tweet back a correction. Not a single one actually responded to what she was actually talking about. It really just came across as "hey look you made a mistake and I'm going to make sure you know all about it."
I just don't get it.