The message utility has been in most "network capable" systems, in one form or another, since the first day when two computers got hooked to each other. It was/is intended for use for messages within a local network.

In order for someone "outside" your network to use the utility, they have to know your "address," and in the old days, that was always hidden behind your network system firewall.

It wasn't much of a problem with dial-up connections, because you get a new address each time you connect, so there's no way for someone to know where you are, unless they "discover you" and make some use of it while you're still connected.

When you switch to a "permanent connection" of one sort or another, you may get a fixed address, or at the least, you may be given a "long term lease" on an address. This allows someone to find your location, and blast you with these worthless messages - until your address changes or until you block their messages. Many internet providers will automatically rotate your connection address periodically to preserve your anonymity, but may not do it very frequently if you're on DSL, WebTV, or some other "hard wired" connection. (And a few have been rumored to sell the new addys when they rotated them.)

Even with dial-up, new Windows systems (WinXP and Win2K at least) assume that everybody wants to be "connected" all the time, so you may find your machine dialing its own connection, and keeping the connection open even when you close your email and browser, for long enough for the spam crawlers to find you and start sending their spam through the message utility.

It's not a new web thing. It's a problem now because of the new way(s) in which we're using the web.

John