I suspect they're doing all of this while on tourist visas, which may or may not be entirely kosher depending on where they're traveling. Of course, it's also

I suspect they're doing all of this while on tourist visas, which may or may not be entirely kosher depending on where they're traveling. Of course, it's also extremely unlikely that they'll get caught (except, perhaps, as a result of bragging about it on the Internet...). A guy, or bunch of guys, sitting on the beach with laptops isn't exactly an atypical sight. Still, they might want to pick their destinations based less on the quality of the beaches and nightlife, and with more consideration towards those which aren't going to try to skewer them for taxes or visa fees if their scheme gets found out.