To the list of things that should not be uttered in modern China, add these: Padded bras cause cancer. The earth is on the brink of falling into a period of darkness for six days. Robots will soon conquer entire industries and eliminate the need for human labor.

These were among the seemingly trivial posts on WeChat, a popular messaging app, that have been censored, according to a study by Citizen Lab at the University of Toronto.

Censorship in China is a well-known phenomenon, with bureaucrats working assiduously to augment the stature of leaders and restrict discussion of topics deemed controversial, such as Tibet and Taiwan. But the Toronto researchers found that these faithful guardians of the Communist Party line have turned their attention to more mundane matters, devoting time and server strength to preventing rumors, fabricated news reports and superstitious premonitions from going viral.

“Online rumors can be viewed as a kind of social protest by citizens skeptical of official news,” explained Jason Q. Ng, one of the Toronto researchers.