In April, the US-based website Change.org launched an online petition regarding China's imprisonment of artist and dissident Ai Weiwei. Soon after that, the site was attacked and disabled. Rep. Rosa DeLauro (D-CT) believes the attack originated in China and had complained to the State Department about it.
In a May 18 letter released yesterday, DeLauro was told that an American diplomat has confronted the Chinese government about the issue directly. "Deputy Assistant Secretary Dan Baer raised the case of Change.org directly with the Ministry of Foreign Affairs while in Beijing" in late April, according to Joseph E. Macmanus, acting assistant secretary for legislative affairs at the State Department. The State Department also called upon China to release Ai Weiwei.
This is further escalation of tensions related to cyber attacks between the US and China. Google has traced a slew of pretty heavy attacks on Gmail to China. The Chinese government denies involvement.