The government hasn't gone out of it's jurisdiction, technically speaking.

Now, do they have the right to do this? Of course not, but not having the right to do something has never stopped the FBI before.

Remember, this is an organization that was created explicitly for the purpose of out-Mafia-ing the Mafia.

From the press release:

... arranged for the money received from U.S. gamblers to be disguised as payments to hundreds of non-existent online merchants purporting to sell merchandise such as jewelry and golf balls