WeChat has reportedly been banned by Australia’s Department of Defence -- again drawing attention to the security and privacy of one of China’s most essential apps.

A spokesman told the Australian Financial Review that it doesn’t support unauthorized apps like WeChat on work devices of staff and serving personnel.

The Department of Defence reportedly allows limited use of Facebook, while it’s still evaluating WhatsApp. 

It’s unknown whether WeChat underwent evaluation, and the spokesman wouldn’t say why the app was banned. But a security expert with government connections told the newspaper there were worries about the safety of user data and over Tencent’s ties to the Chinese government.

Australia isn’t the first country to take this step. Last year India’s Ministry of Defence banned a number of Chinese apps, including WeChat, on work and personal phones -- saying they were “reportedly either spyware or malicious ware.”

There’s even concern coming from within China.

Last month Li Shufu, the chairman of carmaker Geely, voiced his concern about WeChat’s handling of user information, saying Tencent’s chairman Pony Ma “must be watching all our WeChats every day.

Tencent was quick to deny the allegation, claiming the company doesn’t store or analyze user data. But as some pointed out, the company’s own privacy policy -- as well as the country’s recent cybersecurity law -- require it to keep the data to assist law enforcement.

WeChat has become almost indispensable to the lives of people in China. More than just an app to message friends, in China WeChat can be used to play games, order dinner, buy insurance, and pay for things at anywhere from a big shop to a street vendor.

It’s so deeply embedded in society that the billionaire chairman of Lenovo’s parent company said he felt lost when traveling outside China -- because they didn’t have WeChat or mobile payments.