It seems to me that this would have to have a very high level of accuracy and reliability though. Visa overstays amount to a very small portion of total entry a

It seems to me that this would have to have a very high level of accuracy and reliability though. Visa overstays amount to a very small portion of total entry and exit, so if there is even a small false negative rate, ICE agents will be spending a lot of time looking for people who have already left the country.