That people can't read the entire thread, or at least the initial post if the thread is over 3 pages, before they answer a question?
I have seen it time and time again. Someone will explain a scenario and then ask for advice. It never fails that someone will come along and give advice that is something that the OP has listed as being done in the initial post.
I.E: I have this patient and yada, yada, yada. Then we had a consult with so-and-so specialty which said we need to do this. The next few posters will have some good advice then there will be this one poster who you can tell didn't bother to read the entire OP by saying you need a consult with so-and-so specialty so they can do this. HELLO, that was already done and it didn't help.
Now, just to clarify, I AM NOT talking about those threads that run 30 or 40 pages. I'm talking about reading the initial questions before you put your two cents in.