Obviously, if it is located within the US boundaries, it kinda makes sense. For example, there's a sugar spot market along with sugar futures, but does it mean that the CFTC has jurisdiction over sugar spot market somewhere in Shanghai, or elsewhere outside the US? This is meaningless as they don't have jurisdiction there by any means possible.
that's not how jurisdiction works. you know that 110 countries will extradite to the USA, right? bitfinex and tether immediately responded to the subpoenas because the USA is in a position to fuck them.
it doesn't matter where the activity occurs if the united states has mutual legal assistance treaties with relevant governments---
as pointed out above, that's absolutely not how the CFTC views its mandate. they are not restricted to US markets whatsoever.
in fact, the CFTC is charging 1broker in this case. 1broker is an "international" site with CEO based in austria. the CFTC is not charging them for dealing with US securities/markets. they are charging them for unlawful retail commodity transactions (illegal swaps), failure to register and failure to implement AML procedures:
The CFTC’s complaint charges the defendants with engaging in unlawful retail commodity transactions, failing to register as a Futures Commission Merchant (FCM), and supervisory violations for failing to implement procedures to prevent money laundering as required under federal laws and regulations.