Reuters is reporting (link) that the Chinese government has removed several prominent US tech companies from its authorized vendor list meaning government (state) departments or entities are no longer authorized to purchase them. 

This change isn't surprising considering all of the Snowden leaks about NSA spying.  Reuters does mention that some of its unnamed sources said this change is being done to encourage organizations to buy locally rather than for security concerns.

This cuts off a huge potential market for these american firms and it will be interesting to see how they respond.