Altcoinstalk is within US jurisdiction based on this data and if there's a warning they can also impose on their forum what Theymos did, it's still up to the administrator how to decide if the mixers promotions start on altcoinstalk but since the site's domain registrar is GoDaddy they are compliant to US terms.
This is what the Altcointalk admin said about the data protection law of the forum and if the U.S should come demanding for it.