"What the heck? What does it really matter if I use u or you. People still get the point, im not writing to a professor. Jeeeez
and my facts are 98% correct. If I'm wrong, that's because someone gave me the wrong information"
It does matter. The reason that it does is because not using it the right way can give people the feeling that you're not educated and stupid. Furthermore, with regards to the info that you post being wrong. Well, if it is then you are the one who walks away looking bad since you posted it. It doesn't matter. For example, say you're working on an essay for school and all your sources cited came from wikipedia. No educator in their right mind is going to accept wikipedia as a reliable source for anything. So, by using it the teacher isn't going to question the info posted on wikipedia, they are going to question you for being foolish enough for using it.