ICE does this with location data from mobile apps. They simply buy from a private vendor the information about where specific people are. Then they go detain them.
Some real life friends of mine are on a work crew with some migrants. ICE pulled their truck over, asked the migrants to identify themselves (with different names than they’d been using), they complied, and ICE drove off with them after detaining them.
I asked “Did they have their mobile phones with them?” “Yes.” People literally are carrying around a tracking device, voluntarily, with apps installed on them, voluntarily, that report their location to government authorities who want to detain them.