Let's be clear, I am no lawyer and I always follow the laws in all things.
This is just speculation. A company, not based in the USA, whose principals (CEO, etc.) is not living in the USA, and whose assets are not in the USA would be pretty hard to stop or prosecute if it was being traded on a networked, distributed exchange.
Don't let hubris cloud judgement.
Outside the US isn't black and white, more like shades of gray. On one hand you have places like Somolia and on the other you have places like the UK whose government is very friendly to their runaway colony.
Case in point.
http://en.wikipedia.org/wiki/United_States_v._ScheinbergA company outside the US operating servers outside they US, with employees outside the US, regulated and registered outside the US, and owning bank accounts outside the US.
The DOJ with the help of friendly courts in more than 14 countries seized over 87 bank accounts with assets totaling at least half a billion dollars.
Not a single penny was in a US bank account but the DOJ got every last cent along with IP, patents, trademarks, domain names, software source code and sought more than $3B in damages (mostly settled out of court). Players might have their funds returned to them in 2014 if everything goes according to plan.
Guess you aren't familiar with what actually happened there.
1. Nothing like 'every last cent' was seized.
2. The seizures weren't because of the business they ran (online poker) but because of offences related to the banking system.
3. For the 2 largest sites (Stars and Tilt) all player funds of non-US players have already been returned. In Stars' case they never went missing - and US players there got their funds back very quickly. In Tilt's case that only happened after Stars bought them out early this year. With Tilt/Cereus the problem was that the seizures triggered collapse because both were running a fractional-deposit scheme on players' funds - so collapsed when a bank-run occurred post-seizure (Cereus was already in problems even before that).
What got those companies screwed was the way in which they acted to try to circumvent banking restrictions - where similar laws apply across all involved countries. Also a lot of the offences DID occur in the US - where transactions originating and ending in the US were mislabelled to try to get past US restrictions on bank transfers related to gambling.
Which isn't to say it's necessarily safe to sell BTC-denominated shares to someone in the US from anywhere - just that the example quoted isn't a good one to use as the action taken wasn't because of the "selling" but because of the (irrelevant to BTC) offences committing trying to trick US banks into processing transactions.