I'm new to Limewire and file sharing...

Last night I requested downloads for several files... took most of the night to accomplish.. when I checked it this morning, I noticed that in addition to my requested files, I had received an .mpg that I had NOT requested. I know I didn't request it because of it's title, which was audaciously (and hysterically) pornographic, though its contents were not. The problem is, I have no idea where this came from. Is it "normal" to ever receive files you don't request... like a joke file attached to something else? Or is it evidence of someone "getting into my system uninvited" (and all the "hacking" paranoia that would imply).

Please advise.

Thanks...