Alexander Yuan/AP

Censorship on Sina Weibo has gotten much more complicated in recent months.

Through the testing of searches of key "sensitive" terms on the site, it has become clear that some previously-blocked search terms now return results. Don't pop open bottles of champagne to celebrate a decrease in censorship yet, however: an examination of available search results shows that it is instead merely a shift in tactics. The implementation of more targeted, subtler censorship -- including the sanitization of keyword search results to remove unwanted content -- makes the suppression of information more invisible, and harder to fight.

The change has seemingly been gradual, but more starkly came to light recently as scholars and organizations studying censorship found that Sina Weibo was no longer blocking searches for the word "六四" a common way to write June 4, the date of the Tiananmen Square crackdown. While Herdict, China Digital Times, and The Citizen Lab noted that a number of keywords and websites related to the annual commemoration of the 1989 Tiananmen Incident were censored in the run-up to the anniversary of June 4 in 2013 -- some of them being newly blocked and others continuations of longstanding ones -- 六四, one of the most widely-cited examples of what kinds of words are blocked on Weibo, has been inexplicably unblocked, seemingly for good, in China. Though GreatFire first reported that "June 4" was unblocked for intermittent periods in the week before June 4, the latest unblocking serves as the longest the term has ever stayed searchable.

The decision to unblock the term in China is a notable one, as the removal of keyword blocks seems on the surface to be part of a new concerted effort by Weibo to appear more open and transparent. Headline writers and China analysts at a number of international media outlets, including Reuters and The Daily Telegraph, optimistically surmised that the unblocking of the search for Xi Jinping, China's new head honcho, on Weibo ought to be seen as a loosening of restrictions on freedom of speech.