The advocacy group had asked that authorities be required to have probable cause to “zoom in” on people, stating that it’s an invasion of privacy. Daley replied that it would be impractical to ask a judge to find probable cause before zooming in:
[Call] a judge who’s sleeping tonight, at 2 o’clock in the morning, and say "Judge, we have probable cause, the person is walking down 22nd Street." By the time we get there the person’s already at Halsted Street.
The ACLU claims that the surveillance tactics use facial recognition and tracking of a person’s movement, but the city’s Office of Emergency Management denied the use of facial recognition software, saying that the cameras track only objects, not people. The OEM statement did not explain how objects could be tracked without tracking people.