On January 1st 2016 Valve updated their subscriber agreement. Here are the most important parts:
Valve is now selling hardware in the European Union (the Steam Controller and Steam Link). Hardware distribution in Europe will be the primary responsibility of Luxembourg subsidiary, known as Valve SARL.
Digital content and services in Europe move back under our US company, Valve Corp., just as they were before the Luxembourg office opened in July 2012. This is pretty interesting, the company claims that in practice, this changes nothing for our European customers.
Valve claims to continue to operate with respect to relevant European laws, such as local data and consumer protection, and continue to provide the same services they have for years.
Those who simply want to keep playing their games and are not making a purchase at this time are free to simply ignore the SSA update for now. It only takes effect for users who explicitly confirm it, usually during a new purchase.
A full copy of the updated 2016 SSA is available for viewing here.