There's a legal principle call Forum Non Conveniens that is supposed to remedy this, though I don't know if anyone has challenged these seizures on those grounds. Basically, a legal matter is supposed to be tried in the most relevant and appropriate jurisdiction. For example, you sue a corporation in the state where it violated civil law, rather than state where it's headquartered. I shouldn't have to fly to Dallas to sue Pizza Hut if my local franchise poisoned me.

That said, the Internet breaks down a lot of established jurisdictional law because a website can operate effectively anywhere the Internet exists, and as such can theoretically be subject to the laws of any web-connected jurisdiction. These seizures are just another example of how the law has not caught up to the basic operating procedures of the web.

There is a certain legal philosophy that says the Internet is operating under its own version of Maritime Law, which is to say its a non-national zone where the law is defined by consensus practice and then ratified by bordering or participating jurisdictions. International salvage rights emerged from common maritime practice, and are now generally recognized as legally binding.

That's in theory a good model for the web, but I'm very certain the US Government doesn't see it that way.