I have a lot of pet peeves that stem from the internet and how people behave. I guess the top three would be:
1.) Short hand - it's fine for texting I guess, but I don't want to have decipher what people are saying
2.) People who forget/deliberately decide to act rude because they aren't talking face to face with someone.
3.) Odd use of capitalization - there is a time and place for capitalization and people tend to overuse it.
