Basically, if you have any business holdings in the US, host in the US or get CHECKS from the US, you must comply. (That's my understanding).
Maybe they won't 'come get you', but they can sure seize and/or freeze anything you have here if they choose to do so.
In addition, if it were to play out to the max and you ended up with arrest warrants in the US, then that would pretty much make it a tough decision whether to come visit Aunt Millie or even fly over US soil or water.
It's not that hard to comply. I look forward to it. I have software in place and since I already own all of my content with model IDs, anmd I have pages with lists of my perm galleries it's no big step (for my wife, LOL) to get them into a database.
This'll also make it a LOT easier for me to find what I'm looking for when I need a set for something rather than looking thru a hundred CDs for it
AST