I was able to track my phone on Find My and watched this person zoom all around London.
It was actually crazy how fine grain the tracking was actually, I watched them go all the way down Oxford Street, through several tube stops, circle around touristy areas a couple times, etc. Having a phone stolen is panic inducing but at least this was entertaining to see.
I assume they were snatching phones from folks as naive as I and I can't imagine how many phones they must have gathered.