The Los Angeles Board of Police Commissioners voted this month to allow the Police Department to use drones in a one-year pilot program. Whatever one thinks of this technology, the public debate about the issue and the vote by the board, a five-member civilian oversight group, was refreshing — but all too rare. Americans deserve transparency and detailed information about the surveillance tools the police are using or considering, and they’re often denied it.

That’s because there’s intense resistance to offering this information. For instance, a New York City Council bill introduced in March, would require the New York Police Department to disclose any surveillance technology it uses and to make public the policies about restrictions on the use of this technology. But Mayor Bill de Blasio said the bill “provides a road map for the bad guys,” potentially aiding criminals or even terrorists by making them privy to information about law enforcement tactics.

This concern is misplaced. The real risk is that without this type of legislation, the good guys — everyday citizens — will be left in the dark. Police departments should be doing more, not less, to keep the public informed about what tactics they’re using and why.

This is a nationwide issue. That’s why, last year, the American Civil Liberties Union began the Community Control Over Police Surveillance legislative effort, seeking to increase surveillance transparency and allow for input from the communities in cities across the country. This transparency is urgently needed because of something Mr. de Blasio and other opponents of transparency legislation are unwilling to acknowledge: that many modern law enforcement surveillance devices collect information about innocent citizens.