Even so, there is political hostility to surveillance and several commentators downplay the evidence of CCTV's effectiveness, especially in the US.
Gill and Spriggs did a Cost-effectiveness analysis (CEA) of CCTV in crime prevention that showed little monetary saving with the installation of CCTV as most of the crimes prevented resulted in little monetary loss.
First, researchers have argued that the British car park studies included in the meta-analysis cannot accurately control for the fact that CCTV was introduced simultaneously with a range of other security-related measures.
It has been argued that problems of selection bias and endogeneity can be adressed by stronger research designs such as randomized controlled trials and natural experiments.
Today, systems cover most town and city centres, and many stations, car-parks and estates.
More recently, decentralized IP cameras, some equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation. the first commercial closed-circuit television system became available in 1949, called Vericon.Due to these shortcomings, video surveillance was not widespread.VCR technology became available in the 1970s, making it easier to record and erase information, and use of video surveillance became more common.In October 2009, an "Internet Eyes" website was announced which would pay members of the public to view CCTV camera images from their homes and report any crimes they witnessed.The site aimed to add "more eyes" to cameras which might be insufficiently monitored.