I frequent a few message boards. I think we all get annoyed to some degree. What do you get irritated with?

One thing that bugs me is when someone asks a question, you put a lot of thought and time into replying and then you NEVER HEAR BACK from the person.

I also get annoyed at being a thread assassinator (which I've found that I frequently am). You know, I'm the "last person" to post on a thread. I try to tell myself that nobody has anything better to say than what I said but it doesn't always help.

I have many other pet peeves for message boards. But I want to know yours before I go any further.