A DOS does make you semi special... it's probably a DDOS tho... a distributed denial of service attack.
Basically, numb nut crackers go around putting trojans into news groups. Unsuspecting porn nabbers grab it and unwittingly install this thing on their machines.
Once they get enough trojans out there, on enough machines... preferrably on high speed, they can (from the comfort of their own home) press a button and force all of them to start sending junk packets at one destination all at once.... effectively filling up your bandwidth pipe, and making it so that good traffic (real people) can't get thru.
It's a tough attack to protect against... because depending on your ISP, it could be filling their pipe as well, or your pipe between you and them... or just clogging your machine in particular.. it's a nasty little weapon.
My solution... track the f*cker down and use my fav anti-virus weapon... a gun
