[christophclarke]

Crimes committed against the United States are seen as crimes committed in the United States. This is an issue of sovereignty, as there is no (for most intents and purposes) higher, international court to pursue the case in. Therefore, the case is tried in the United States. It's similar to any other foreign national conspiring in crime in the United States. They don't have to physically be in a country to break a country's laws.

The country that the individual was in when the crime was committed can certainly handle the issue and not extradite, however, generally these agreements avoid that.

This existed before the internet as well.

[lostmyoldone]

If US acknowledged international courts, you could make that argument. But as of now, the US doesn't acknowledge some of the most important international courts, like the ICC. Thus the argument that there are no higher courts is entirely bogus, as it is so by choice.