Looks like Hosting Matters is being hit again today. Little Green Footballs and Instapundit (among probably others) are unreachable again.

[Update in the afternoon]

For those who need your Instapundit fix, here's his backup site.

This is the fourth Hosting Matters DOS attack in a week, if I'm counting right.

yup, looks like they're having some problems, and routing of traffic isn't helping. according to hostingmatters forums, they are changing IP addresses for their servers. Pretty harsh stuff.

I know less than nothing about these things, so I'll ask a stupid question: Is there some way they can attack back?

Not without openly commiting a federal felony!

And most of the systems used to launch such attacks aren't themselves owned by the attackers, but have generally been hacked or infected with a virus/worm by the attackers, who have the compromised remote system under their control

So from a legal standpoint, most attempts at online self-defense would actually be doing further harm to other fellow victims of the ultimate attacker.

Retaliation therefore would usually open up the defending party to a potentially large tort liability, as well as running afoul of computer intrusion and/or telecommunications and privacy laws.

In cybercrime, an attack is an attack under the law, whether or not it's in self-defense, at least under US law.

(Disclaimer: While not a lawyer, I have been a networking and security professional for over 10 years. Your milage will vary depending upon your local jurisdiction.)