The installation of cameras in classrooms may be objected to by some teachers. There were an estimated 30 million
surveillance cameras in the United States in 2011. Video surveillance has been common in the United States since the 1990s; for example, one manufacturer reported net earnings of $120 million in 1995. With lower cost and easier installation, sales of home security cameras increased in the early
21st century. Following the September 11 attacks, the use of video surveillance in public places became more common to deter future terrorist attacks. Under the Homeland Security Grant Program, government grants are available for cities to install surveillance camera networks. In 2009, there were an estimated 15,000 CCTV systems in Chicago, many linked to an integrated camera network. New York City's Domain Awareness System has 6,000 video surveillance cameras linked together, there are over 4,000 cameras on the subway system although nearly half of them do not work, and two thirds of large apartment and commercial buildings use video surveillance cameras. In the Washington D. C. area, there are more than 30,000 surveillance cameras in schools, and the Metro has nearly 6,000 cameras in use across the system.
home alarm
For example, the smart home environment 100 may include a pool heater monitor 114 that communicates a current pool temperature to other devices within the smart home environment 100 and/or receives commands for controlling the pool temperature.
THERES JUST NO U'S.
- alarm system for house
- wireless alarm systems for the home
- home security reviews