Mike the Musicologist tipped me off to this:
Marcus Hutchins, the guy who was in the news earlier this year for defusing the WCry malware, was detained in Las Vegas after DEFCON.
This is still an evolving story, but what I’ve seen from reliable sources (and CNN) is that Hutchins is under federal indictment and charged with creating another piece of malware: Kronos, described as a “banking Trojan”.
The best coverage I’ve seen of this so far is from TechDirt and ArsTechnica. I would keep an eye on those two sites for updates, as this story is still evolving.