I find it interesting that a Polish man was charged by US laws, rather than under Polish law. I think he opened himself to US law by hosting the servers at one point in the US. Regardless, it is rather fascinating that his first visit to the US could potentially be from extradition.
Anyone doing things that affect the US is automatically subject to US jurisdiction. But whether they can be extradited depends on the particular treaty the country in question has with the US.
Other than drugs and murders, I have a hard time believing US govt to give out its citizens to third parties...