The chief spokesman for Baltimore police insists that a trial program in which a manned plane with cameras flies over the city and feeds information to law enforcement was not a secret.

T.J. Smith told reporters at a news conference Wednesday that the program, first reported Tuesday by Bloomberg Businessweek, was another potential tool in the department's crime-fighting arsenal.

Smith said the program is a test between the department and Persistent Surveillance Systems, a company that wants to sell the service to Baltimore.

The ACLU of Maryland expressed outrage at the program, saying in a statement it's "a privacy nightmare come to life."

Smith, pressed by reporters to explain why the privately funded program was unknown until the Bloomberg report, compared the plane to Baltimore's hundreds of CitiWatch cameras.