TikTok can now add the U.S. army to the range of American critics looking into privacy and security concerns related to the popular Chinese video app.

Army Secretary Ryan McCarthy said a security assessment will be done of the app, which has been used to recruit teenagers into the military. U.S. Senator Chuck Schumer of New York had called for the investigation, saying there were legitimate concerns about TikTok’s collection and handling of user data.

TikTok scrutiny by the U.S. government has soared as downloads for the short video site pass 750 million worldwide. The government is investigating TikTok’s relationship with China amid reports that its Beijing-based teams have restricted videos deemed subversive or controversial by the Chinese government, including political speech.

Alex Zhu, TikTok’s chief, told the New York Times this month that Chinese authorities don’t control the company and that TikTok doesn’t share user data with the government. Also, the data isn’t available to parent ByteDance’s artificial intelligence programs, he said.

TikTok officials declined to testify at a U.S. congressional hearing earlier this month at which security experts and lawmakers painted a gloomy picture of cyber espionage. Americans are confronting “deep systemic risk” when using platforms operated or owned by companies in China, testified Kara Frederick, a fellow for technology and national security at the Center for a New American Security.

U.S. social media giants including Facebook and Twitter have also faced concerns over the security and privacy of user data. Those concerns have pushed private investments in AI-powered cybersecurity startups above $1.27 billion this year, surpassing 2018’s $961 million, according to PitchBook data.

  • ByteDance’s $1 billion purchase of Musical.ly, a company Zhu founded, is under a U.S. National Security Review, and is being probed by the U.S. Committee on Foreign Investment, Reuters reported this month. Preliminary discussions by the committee are underway, USA Today reported, citing an unidentified official. 
  • With 26.5 million monthly active users in the U.S., TikTok’s popularity skyrocketed after the acquisition of Musical.ly two years ago. ByteDance has more than 1 billion users globally.
  • U.S. Army cadets have been told not to use TikTok while in uniform or performing official duties, though they can still turn to the app for personal use.