Access means 24/7/365 access by the way. They can keep the data and run backward through it to see exactly who was on that street corner at 2pm on the second Tuesday of September 2015. They can also, given sufficient horsepower, do a facial recognition pass on accessible cameras and see if Person Of Onterest X has -ever- been in front of that camera.
Computer scientists have created a way of letting law enforcement tap any camera that isn't password protected so they can determine where to send help or how to respond to a crime. "It's a way to help people take advantage of information that's out there," says David Ebert, an electrical and computer engineer at Purdue University.
The system, which is just a proof of concept, alarms privacy advocates who worry that prudent surveillance could easily lead to government overreach, or worse, unauthorized use. It relies upon two tools developed independently at Purdue. The Visual Analytics Law Enforcement Toolkit superimposes the rate and location of crimes and the location of police surveillance cameras. CAM2 reveals the location and orientation of public network cameras, like the one outside your apartment. You could do the same thing with a search engine like Shodan, but CAM2 makes the job far easier, which is the scary part. Aggregating all these individual feeds makes it potentially much more invasive.
Beyond the specter of universal government surveillance lies the risk of someone hacking the system. To Maass, it brings to mind the TV show Person of Interest and its band of vigilantes who tap government cameras to predict and prevent crimes. This is not so far-fetched. Last year, the EFF discovered that anyone could access more than 100 "secure" automated license plate readers. "I think it becomes a very tempting target," says Gautam Hans, policy counsel at the Center for Democracy & Technology. "Thinking about security issues is going to be a major concern."