From Diego Doval, (well, actually I first saw it on the Jabber-dev mailing list, but blog-links are neater) I learn that AOL has patented instant messaging, thanks to a 1997 filing by ICQ.

Before you scoff about patenting the obvious, try to remember back to just how revolutionary ICQ was, and how quickly everyone flocked to it. ICQ introduced the idea that presence would work over the Internet, not just on closed-gate BBSs and online services. People flocked to ICQ in their millions, almost from the moment it was released, because at the time there was nothing like it, and nobody was attempting anything like it.

Sure, in retrospect it seems obvious. If it was that obvious, though, why didn't anyone even try it until the late 90's? And there was lots of art beforehand that could be considered inspiration. But I think the patent certainly has merit as being an invention of something novel and non-obvious. Before ICQ, you either had email, or you had IRC, there was nothing in between. After ICQ, every man and his dog was suddenly talking about instant messaging, presence and P2P.

That said, I think this is a prime example of why patents shouldn't apply to a rapidly developing field like the Internet. The law lags so far behind the innovation that by the time the patent is granted, there are several large players fighting over an established market, and the people who had the idea have already cashed out and sold their stake to a monolith who had nothing to do with the innovation itself. The patent, intended to be an incentive that stimulates advance, become a bludgeon by which it is crushed.

We need a better system. More on that anon, perhaps.

Luckily, IMHO, this patent is unlikely to ever be enforced. Of the other players in the IM game, Yahoo! probably isn't worth suing, Jabber certainly isn't, IBM will just look through its filing cabinet and say “Oh, we noticed you're violating about fifty of our patents just by breathing, I don't suppose you want to do a swap?” and Microsoft can afford to throw enough money at lawyers that they can prove the patent doesn't apply to them. At worst, AOL will just hold the patent up its sleeve against the day it needs a favour that costs less than the lawyers required to tie it up in court.