No idea.
... but there's millions of retards out there with windows computers with viruses in them that give control of their computers to other people.
Those (few) people who control them, want to do something with all those computers they control, so they often sell them to others to attack web sites.

Every once in a while someone comes in here and rants and raves about something and I end up deleting their dozens and dozens of posts, while they claim that I shouldn't be allowed to delete their posts ...
I guess that type of person might consider DDoSing the web site, or asking someone else to do it.