A MAC address is a unique and fixed identifier assigned to an internet-connected device — which means it can be repurposed for tracking the individual user for profiling and ad targeting purposes, including by being able to re-link a user who has cleared their advertising ID back to the same device and therefore to all the prior profiling they wanted to jettison.

And while no popular social app platform has its hands clean when it comes to user tracking and profiling for ad targeting, TikTok being owned by China’s ByteDance means its flavor of surveillance capitalism has earned it unwelcome attention from the U.S.

government is able to point to China’s internet security law, which requires firms to provide the Chinese Communist Party with access to user data — hence TikTok’s emphatic denial of passing data.

Yesterday it emerged that France’s data protection watchdog has been investigating TikTok since May, following a user complaint.

The CNIL’s concerns about how the app handled a user request to delete a video have since broadened to encompass issues related to how transparently it communicates with users, as well as to transfers of user data outside the EU — which, in recent weeks, have become even more legally complex in the region.

If TikTok was concealing its tracking of MAC addresses from users, it’s difficult to imagine what legal basis it could claim — consent would certainly not be possible.