No more so than stocks, bonds, ETFs, or anything else that can be transacted outside of the country where originally purchased.
"8) Bitcoin will continue increasing in popularity and value, Amazon or another major retailer will announce acceptance of the virtual currency. Bitcoin will continue to have wild price swings, increasing in value to $2,500 or higher during 2014. Bonus predictions: Edward Snowden gets some type of pardon and returns to the United States. Fukushima has another meltdown or emergency, as the public has never been told the true extent of the problem."
Other interesting predictions for '14 at the link above.