<p>To tell you truth, i have never been an IM’er, but i have seen my son and daughter put people on the blocklists. Not sure what they see on the other end. I think that you can also setup the IM, such that ONLY people on your BUDDY list can contact you. In that case, you have to manually define those people who you wish to communicate with, all others never get through. Again, not sure what they see on the other side. I’m sure some of the many IM’ers will answer your question (in case there are more details).</p>