Yes you would think that they would use some sort of hardware firewall to minimise these attacks. I have just tried to get on to the Register Website a few minutes ago but I am shown "Website not responding (Error 502)": click here
To prevent all DOS attacks you would have to tie your server down to a state of uselessness, it would be pointless having it. You can set filters at the firewall on the DNS server and set policies to only allow address's from a legit ISP and killing responses but if someone has enough zombies there is no way of stopping a DOS attack.
A prank could be the reason as CurlyWhirly suggests because some people have the weirdest (or most perverse) sense of homour.
I've been receiving the Register's newsletter for a while and they don't seem to be doing anything more to upset the virus writers /spammers than anyone else so, as you say, it really does not make any sense to target them.
But I've never been sure how it is accomplished. Is it done by loading a virus on people's PCs?
Re the tyres chap - was that the one in Dorset? he seems to have had some kind of hatred for car drivers and from what I read could have been a candidate for an asylum rather than prison! But then so could these people.
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