With Carnival season around the corner, New Orleans officials have green-lit the installation of 250 surveillance cameras across the city — part of a $40 million security plan announced by Mayor Mitch Landrieu last year.

The cameras are lit by blue and red flashing lights to make them more visible, the New Orleans Advocate reports. The colors are meant to assuage residents’ concerns while preventing crime, but concerns linger, particularly among privacy advocates.

“While presented as an innocuous measure to reduce crime, this heavy-handed government surveillance mandate would impose exorbitant costs, violate the constitutional right to privacy, undermine trust with the community and have a chilling effect on our public spaces — without reducing crime or making the city safer,” the ACLU of Louisiana wrote last December. The organization added: “Surveillance technologies are shown to have a disparate racial impact, with black people more likely to be misidentified as suspects and disproportionately placed under surveillance.”

For Carnival season, extra cameras are also being installed along prominent parade routes. Other safety features that will go up during this year’s festivities include bollards to block vehicle attacks on Bourbon Street, mobile barriers for the French Quarter and devices that can detect chemical, biological or nuclear weapons and explosives.

New Orleans isn’t the only city boosting its stock of surveillance cameras. In June of last year, the New York Police Department had about 2,000 street-level cameras scattered throughout the city’s public spaces — and officers had access to about 4,000 more private cameras as well. Even so, 12,000 New Yorkers reported last year that they believed the city needed more cameras on its streets, even though crime had hit historic lows.

New York’s surveillance system has also raised a number of red flags among privacy advocates.

“The social implications of the city’s ever-expanding surveillance network has prompted the New York Civil Liberties Union to push back at times,” Will Doig wrote for Next City last year. “Its 2006 report, written when the city’s camera network was still in its infancy, warned, ‘We are witnessing in New York the creation of a massive video surveillance infrastructure.’ Of particular concern was what happens to footage after it’s recorded — the report cites New York’s rich history of using surveillance to crack down on particular groups, from suspected communists to Vietnam War protesters.”

Rachel Dovey is an award-winning freelance writer and former USC Annenberg fellow living at the northern tip of California’s Bay Area. She writes about infrastructure, water and climate change and has been published by Bust, Wired, Paste, SF Weekly, the East Bay Express and the North Bay Bohemian

Follow Rachel .(JavaScript must be enabled to view this email address)