so a stranger sends me an IM

[Wynton]

While multitabling the other day, I inadvertantly accepted a stranger onto my contact list. It was simply a misclick. But I didn't get an actual message at the time, so forgot about it.

Today, this guy (apparently a guy)sends me a message. By this time, I realize I have no idea who he is. (On the other hand, my brain is fried and I forget half the people I actually know.) So, I ask who he is, and he responds by asking who I am. When I don't give any info, he starts harassing me, and I block him.

My question is whether this kind of thing is routine, or has ever happened to anyone. Is sending out IMs to strangers some kind of common ploy that I'm clueless about? Does this actually amuse some people?