窃听器 (hidden microphone / qiètīngqì), also commonly known as a bug, is usually a combination of a miniature radio transmitter with a concealed microphone.
Why it is blocked: Chinese activists and foreign officials have long been concerned about the police bureau’s surveillance capabilities, especially its ability to wiretap phones. A 2011 Times article opened with an anecdote about a phone conversation being cut off after a caller said the word “protest.” The story elicited much amazement at the time but has since been viewed as likely to have been a fluke occurrence, at best. Even so, Chinese surveillance capabilities are quite high and such intrusive/heavy-handed tactics are not so uncommon. A recent Times story documents some of the measures U.S. officials take to prevent Chinese monitoring and hacking. [Status - 12/20/11: blocked; 2/5/11: unblocked]
