"If your message contains a keyword from the list then the message is not sent," the report explains.
The list of banned words contains a lot of things you would expect — sexually explicit content like "young girl undressing" and "nude video chat," terror-related terms like "improvised explosive devices," and politically sensitive information like "Tiananmen Square massacre." But a lot of it is reactive.
In fact, the lists of banned keywords varied dramatically.
"This suggested that there's no centralized list sent to the companies by government authorities," Crete-Nishihata said.
"Here you see, over the past year, an industry and a type of application exploding in popularity and it's offering users in China new and fun ways to express themselves and connect," Masashi Crete-Nishihata, research manager for the school's internet watchdog Citizen Lab, told CBC News.
"But these expressions and connections are also threatening to the government.
Keyword monitoring and filtering — just one way the companies crack down on unwanted speech — works by embedding a list of banned terms within the application itself.
While China exerts direct control over news media, it appears to take a more hands-off approach with private companies.
As live streaming apps surge in popularity in China, the companies profiting from the craze are pulling out all the stops to censor millions of users and avoid the wrath of a government intent on maintaining a tight control over the flow of information.
A new report from the University of Toronto's Munk School of Global Affairs describes how China's biggest live streaming apps work to shut down discussion on everything from sex and gambling to political gaffes and government corruption.
"Keywords will be added in and around a particular news event," Crete-Nishihata said.For example, last month when an translation error caused President Xi Jinping to tell G20 leaders that China's economic policy aims to "loosen clothing," the apps added a total of 17 keywords that referenced the speech.