I completely agree they're a thing, but at what scale? The current administration has deported something like 600,000 illegal immigrants. What do you think their accuracy rate is carrying out those deportations? An accuracy rate of 50% would mean there'd be 600,000 errors. An accuracy rate of 70% would mean we'd expect to see around 250,000 errors. An accuracy rate of 90% would mean we'd expect to see around 67,000 errors.

A quick search [1] on this topic showed 50 people have been wrongfully detained. Even if we increase that figure substantially, it implies an extremely high success rate, which isn't really possible if you're just engaging in widespread fishing expeditions.

[1] - https://www.propublica.org/article/immigration-dhs-american-...

Stopped ≠ detained. The government doesn't release stats on who was stopped. Kavanaugh stops are literally about using race as a criterion for the stop. No other probable cause is required.