New York City Police Commissioner Bill Bratton envisions a day when officers can monitor subway cars armed only with a tablet. “One of my officers could actually be standing on a platform waiting for that train to come in,” he told the New York Daily News, “monitoring the cameras on that subway car to see if there’s an issue on that 10-car train that he wants to go and focus on.”

The Metropolitan Transportation Authority (MTA) may follow the example of the Chicago Transit Authority (IL), which attributes a drop in crime to new surveillance cameras in rail cars.

For now, the MTA has not committed to in-vehicle cameras but the authority is looking into the possibility.

”They could potentially improve safety and security for our customers, but creating real-time monitoring capabilities would be a difficult technical challenge,” said MTA spokesman Adam Lisberg.

Reactions were mixed. ”Cameras are ubiquitous throughout the system. Why not inside train cars?” asked John Samuelsen, president of Transport Workers Union Local 100.

“Anything that improves security and helps our conductors keep riders safe is a positive.”

But privacy advocates urged caution.

“As everything we do is being caught by government cameras and stored in government databases, common-sense privacy protections become all the more important,” said Christopher Dunn of the New York Civil Liberties Union. “For starters, recordings of subway riders should be promptly erased unless the MTA receives a report of a crime or injury.”