  Location tags are designed to track personal belongings. Nevertheless, there
has been anecdotal evidence that location tags are also misused to stalk
people. Tracking is achieved locally, e.g., via Bluetooth with a paired phone,
and remotely, by piggybacking on location-reporting devices which come into
proximity of a tag. This paper studies the performance of the two most popular
location tags (Apple's AirTag and Samsung's SmartTag) through controlled
experiments - with a known large distribution of location-reporting devices -
as well as in-the-wild experiments - with no control on the number and kind of
reporting devices encountered, thus emulating real-life use-cases. We find that
both tags achieve similar performance, e.g., they are located 55% of the times
in about 10 minutes within a 100 m radius. It follows that real time stalking
to a precise location via location tags is impractical, even when both tags are
concurrently deployed which achieves comparable accuracy in half the time.
Nevertheless, half of a victim's exact movements can be backtracked accurately
(10m error) with just a one-hour delay, which is still perilous information in
the possession of a stalker.
