YouTube is in hot water over claims it engaged in censorship on behalf of the Chinese government.

In a letter to Google and Alphabet CEO Sundar Pichai, Senator Josh Hawley asked for an explanation about the alleged censorship. YouTube has explained the censorship occurred as a result of an error in its enforcement system, but has provided very little information beyond that. Understandably, the explanation is doing little to ease people’s concerns.

In his letter to Pichai, Hawley says “that Google engineers may have changed the algorithms on YouTube to automatically censor certain criticisms of the Chinese Communist Party. In particular, Google engineers appear to have altered YouTube code to automatically block the Chinese terms for “communist bandit” and “50-cent party”—the latter term referring to a division of the Chinese Communist Party whose purpose is deflecting criticism from the Party by using sockpuppet accounts to spread online propaganda. These reports follow in the wake of Google’s purported ‘mis’-translation last year of the phrase ‘I am sad to see Hong Kong become part of China’ to ‘I am happy to see Hong Kong become part of China.’”

Senator Hawley gave Pichai till June 12 to respond. It remains to be seen if Google will provide concrete information on the issue.