On December 16, the Pentagon sent a Cyber Awareness Message that identifies the potential risk associated with using the TikTok app and directs appropriate action for employees to take in order to safeguard their personal information, The Guardian reported. The message also advised military personnel to uninstall TikTok to circumvent any exposure of personal information. The following week, the Navy banned TikTok from government-owned devices. A Navy bulletin said that members with TikTok accounts who didn't remove the app from devices would be blocked from the Navy intranet. A Navy spokesperson told The Guardian that generally, Navy personnel are allowed to use social media apps, although sometimes specific apps thought to be security risks are banned. TikTok was a tool used by the Army for reaching and recruiting Gen Z, until it was banned from government-owned devices in late September, Military.com reported. An Army spokesperson told Military.com that TikTok is considered a cyber threat, and that while the Army cannot ban members from using it on personal devices, it does recommend caution. The threats posed by social media are not unique to TikTok (though they may certainly be greater on that platform), an Air Force spokesperson told The Wall Street Journal. Videos of jet stunts and troops jumping out of planes tend to go viral on the app, and may also pose an additional risk, the Journal reports.A Coast Guard spokesperson told The New York Times in January: TikTok is not an application currently used on any official Coast Guard device. He also said that Coast Guard members go through an annual cyber awareness training. This decision is consistent with our efforts to proactively address existing and emerging threats as we secure and defend our network. This block only applies to government-issued mobile devices, a spokesperson told The New York Times.On February 22, Schumer sent a letter to TSA Administrator David Pekoske about the agency allowing TikTok use, and he cited a policy from the Department of Homeland Security the prohibits TikTok on devices, the Associated Press reported. TSA is an agency within DHS.On February 23, the TSA released a statement saying a small number of TSA employees have previously used TikTok on their personal devices to create videos for use in TSA's social media outreach, but that practice has since been discontinued, the Associated Press reported.