There are no restrictions on use with personal devices, but officials have encouraged personnel and their kids to uninstall the app.

The Air Force and Coast Guard didn't provide specific reasoning for the ban, but it's likely to be consistent with earlier bans. There's been concerns that TikTok's ownership might leave it susceptible to pressure from the Chinese government to hand over sensitive data, although the company recently said that China didn't request any info in the first half of 2019.

And like spokeswoman Maj. Malinda Singleton told the WSJ, some of the issues are "not unique" to any one social media platform. Hostile governments could theoretically recruit people through social networks, and there's a chance that personnel could inadvertently reveal military secrets or expose themselves to attack. Warnings like this are rare (the Defense Department cautioned against using Pokémon Go in 2016), but they're not shocking given the potential for oversharing.