Interesting article on the details of what he's charged with here, with screenshots of the operation he stands accused of running.
While the details of the arrest are still hazy, one thing is clear - they've had this guy in their sights since 2011. It's not surprising that they issued a sealed indictment for him, mind you, that's not particularly unusual for a case like this where the subject is unlikely to be extradited and would avoid your jurisdiction if the indictment was public (nor is the US in any way unique in this regard). And since I've seen others commenting about this: yes, the Secret Service is the correct body to have jurisdiction over this, as they (strangely) are in charge of enforcement against financial crimes. Back in the early days of commercially available inkjet printers, the nerdy high school/college program I went to (TAMS) once got a visit from the secret service when one of the students figured out that he could print good enough replica dollar bills on one to fool the scanner on the drink machine in the lounge. The total volume of the forgery had to be tiny, I'd be surprised if it was more than $100, but still, if you feel like getting involved in financial crime, expect the Secret Service to be looking out for you. ;)
The scandal here would be if this was an extrajudicial "kidnapping" in the Maldives, with the US swooping up in a van, grabbing the guy, and jetting him off to Guam to use as a bargaining chip, as has been alleged by the guy's MP father. I seriously doubt all that, but we'll see where the truth lies.