I just got around to disabling this little service, but not before I got another message from someone telling me:
“Tired of getting popups? This shows there is an open port on your computer, where hackers can get in. If you send me $10 I can help you stop this.”
Well, this particular message had an actual address to send payment to. And a last name. So needless to say, I have a phone number to the residence, now, as well.
First: Is there something I can do to this person… legally, that is? (I am guessing probably not, but still)
Second: Do you think this is the person’s actual address? I would be leary about it at first, but I’m sure there are people who have sent money to the address, so I could definitely see the contrary.
Please share any opinions, or suggestions with me on this. 
LilShieste
Sadly, no. Though the fellow is a bozo there really isn’t anything you can do to him.
The thing is that the Internet is, just as the name implies, a network. You can do all the things on it that you could do on any other network (albiet much more slowly). What spam-boy is doing is using a program installed on all Windows machines to send a message. The command is “NET SEND” and it can cause a pop up message to appear on the screen of anyone who has the appropriate network features installed. Those features are installed by default on Windows 2000 and Windows XP.
In this case our loser has likely written a very simple script to send out a message likely to all IP’s sequentially. He doesn’t care if the message is recieved or not since he can hit the entire Internet in a time frame measured in hours and start over again.
In his direct actions he’s doing nothing illegal. However, let me save you ten dollars. If you go to your control panel you’ll find an icon for administrative tools. Under that go to services. Look in the list for Messenger. You can change it from automatic start to disabled and never see those messages again. Or you can download some firewall software like ZoneAlarm and let it shield you from this kind of elementry attack.
Unfortunately there’s no convenient way to backtrack the dorks who do this and get their ISP account cancelled. This one may have given you his name and address but for getting the ISP that doesn’t help. If there is a website attached to it then I recommend looking up who hosts it and reporting it to their abuse department at least…
Bah… Well, thanks for the info, Just Some Guy. I had disabled the Messenger Service just after I received this popup, because I was getting tired of getting them weekly. Oh well… I don’t really need the extra hassle of doing something in retribution anyway. 
LilShieste
This is more of an MPSIMS thing, so I’ll be shooting it over there. You can thank me later.