Adam, read the post by the same name under the "is it worth it?" section. If someone in the US is hosting a site overseas that breaks US law, he can still be held legally responsible.
And, to make this point: calling people en masse to harass them is harassment. It doesn't matter if no threats are made; there is no mistake about intent after the first call. If one person is getting dozens or hundreds of calls from a large group of people, forcing them to change their number/phone provider/etc, it's become a possible civil case as well as criminal case.
Someone who operates a site that gets all of these harassers together, gives them resources on how to commit their crimes without detection, encourages people to take place in these actions, and even gives them the opportunity to introduce new victims is legally responsible for every single call made to one of the numbers on his/her site. The webhost, as well, is in the wrong, as no good webhost is going to host a site without knowing the content. Since most of these bombs take place interstate, they (can) become felonies. As the webhost is knowingly abetting felons, he could get all his equipment pulled and his business shut down while the case is going, and the fines would be high enough that he may not re-open.
Think about the mafia. Just because the Don may not commit crimes himself, he is legally responsible for every single crime committed by the mob, just as every other mobster is legally responsible for their own actions and actions they encourage others to take.
The reason no crimes were mentioned in the news report is because charges haven't been filed yet. The DA probably figured it would be easier to shut down the site than try to get enough info on the webhost, PB, and the regulars to prosecute them all. I'm doubting they'd be that generous a second time around, especially if PB were to try to escape prosecution by moving the site overseas but still keeping his name on it and his hand in it.