My college dorm's Laundry webservers were slashdotted but someone was still able to come along later, patent the idea, and try to sue us.

... which is just another example of that which has long been implemented (and sometimes long been patented) still managing to attract protection. However, at least when there is a significant pre-established publication of the idea the 'try to' becomes rather more significant than the 'sue' and they can be got rid of rather more easily.

Yes, and really it wasn't much of a problem for us. The company still has a monopoly on the laundry-webserver business, though, and overcharges other people horribly.

Hmm. If this sort of thing is happening with any regularity the other side of this argument is that there needs to be a clearer, simpler way for patents to be struck down. If it's not valid for one it's not valid for any and any other position is dangerously close to extortion.