The concern arises from the exposure of TikTok to the Chinese government through parent company ByteDance – according to Chinese cyber security laws, all Chinese companies must submit requests for user data to the Chinese government upon request. This does not necessarily mean that the Chinese government is asking for this, and TikTok has repeatedly stated that it does not store US user data in China, thereby limiting potential exposure. But the lack of transparency around the Chinese regime and its processes continues to cause concern, and may eventually force TikTok to drastically change its ownership profile or run the risk of losing it in certain markets.
The concerns of the American army are logical. Miltary and Navy crews perform different secret operations at any time, and data collected by TikTok use may unintentionally expose their locations, leading to conflicts. For example, if the US military were to follow Chinese activity in the South China Sea, a specific point of tension in recent times, that could be problematic – if the Chinese government were indeed to request and / or consult such data from ByteDance.
But should the same concerns relate to regular users of the app?
Clearly there is a problem with the potential of Chinese government intervention – but really, what data does TikTok actually have? What could be deduced about your own personal use if such access were granted?
The problem here is more related to scale than to case-by-case scenarios. You may not be personally concerned about sharing your data in the app – you may find it not a big deal if a company or organization has access to your name, phone number, email address, etc. But with a sufficiently large sample set, the data extracted by TikTok can reveal a lot – and the recent data privacy issues of Facebook show how exactly such data can be misused.
For example, suppose you have an active TikTok profile and TikTok records what you view, what you upload, along with your personal bio information, location data, etc. This in itself can be harmless, but through your app use, you create a data profile that can be compared with other users, and eventually, with sufficiently correlating data points, trends begin to emerge.