Orin has already blogged this, but it's worth another look.
The defendant, located in Colorado, issued an online prescription to a patient in California. He never actually communicated directly with the patient; the patient had filled out an online questionnaire distributed at a website physically located outside of the US; the website was owned and operated by a Florida corporation, which forwarded the questionnaire to the defendant, and to whom the defendant directed his response; the Florida company then sent to a pharmacy in Louisiana, which shipped out the medication to the California patient.

The defendant was then charged, in California, with "practicing medicine without a license . . . in San Mateo County, California" (where the patient was location and where the medicine was shipped). The defendant argued that California could not exercise jurisdiction over him, or charge him with practicing medicine "in California," because he had never set foot in California, he had no agents acting on his behalf in California, and he had not communicated directly with anyone in California.

The court disagreed:

"Territorial jurisdiction to prosecute lies under the traditionally applicable legal principles, and it makes no difference that the charged conduct took place in cyberspace rather than real space."

Orin, I take it, agrees; he thinks this is a reasonable -- perhaps even an obvious -- resolution. "Next time," he writes, tongue presumably in cheek, "maybe the defendant should argue that if you commit a crime in cyberspace rather than real space, you only have to go to cyber jail instead of real jail."

Well, I'm not so sure it's so reasonable. There's a very deep problem here, and it won't go away just by saying "it makes no difference that the charged conduct took place in cyberspace." Here's the issue, in a nutshell. The court is probably correct that the "traditionally applicable legal principles" permit it to assert jurisdiction over the defendant; the harder question is whether those "traditionally applicable legal principles" become utter nonsense in a networked world.

The "traditionally applicable legal principle" here is what the court calls the "detrimental effects theory" of extraterritorial jurisdiction: if your actions outside the jurisdiction have harmful effects inside the jurisdiction, you're subject to the jurisdiction's criminal laws.

This principle, I submit, doesn't make sense in a world in which the "effects' of all actions are felt instantaneously everywhere on the network; applying that principle leads to the conclusion that everyone is subject to everybody's criminal jurisdiction simultaneously, and I don't think that is a sensible conclusion for a global legal system. Orin, I take it, will have no objections when the State of Slobovia, which has very strict rules about the unauthorized practice of law, declares him to be criminally liable for violating those rules in his postings here on the Volokh Conspiracy -- but I'll defend him in that proceeding, nonetheless.