What is the legacy of the Tiananmen Square protests?

Available for over a year

Security is tight in Beijing, on the 25th anniversary of the massacre of protesters in Tiananmen Square. It's still not clear how many people were killed in the pro democracy demonstration. Any attempts to commemorate, discuss, or report the events which took place in 1989 have been banned. In recent weeks, dozens of activists, critics and lawyers have been detained. What is China's legacy since the protests? And what did the protests achieve?