They said they retrieved IP addresses and "routing information", doing fine grained geo ip lookups is impossible, but the accuracy of country of origin is very high, especially in the US

> geo ip lookups is impossible

impossible is the wrong word here, its just unnecessary. The Feds can (and do) definitely contact domestic & international ISPs to perform near 100% accurate lookups.

To go back to the car analogy this is like the police getting approval to shoot the tires and then closing their eyes when they pull the trigger.