I get annoyed and often a little angry at idiots I meet on the internet, particularly in forums and online games. However, once I turn off my computer, I've pretty much forgotten about it. I've never let anyone's words on the internet ruin my day, because I guess I'm just used to being surrounded by idiots and just shrug it off after a while.
I think the only time I got a little sad was when a good e-friend of mine had this terrible mood-change that lasted a month, and they basically told me that they don't care about talking to me because I'm just a guy on the internet and our friendship is pointless. At the time, I was kind of young and found it shocking how people don't take the time to realise that there are OTHER PEOPLE on the other side of the internet. But hey, after settling in more, I realised that most people are basically like that and you can't really treat conversations here like conversations in real life.
I do appreciate one thing of this aspect, and that is the lack of hypocrisy. On the internet, people are more likely to tell you that they hate you or your work, as opposed to most people who couldn't tell you that in real life. I guess, despite the lack of consideration for human feelings, I also like honesty.
The only thing that concerns me is the need to be nasty just because you visualize a person as nothing more than a size 8 font on your screen. But, I've learned to care less about it.