Do you IM your friends immediately when they get online?

That's annoying, I had the same bloody problem with one of my friends. The solution, I blocked, what did I told him when he asks why I don't respond him: I wasn't online, maybe you're PC has a hacker, spyware or virus. But I think (if is not an life/death situation) is rude to IM as soon you're online. You feel like chased or something like that :S