Video surveillance cameras first came to America in the 1960s when federal law directed U.S. banks to install them as a security device.

In the 1970s, they popped up in hospitals, art galleries and convenience stores. In the 1980s, as the technology advanced, they spread to hotels and retail stores.

Then a series of deadly incidents in the 1990s -- bombings of the Oklahoma City federal building and a park at the Summer Olympics in Atlanta, and the mass shooting at Colorado's Columbine High School _ triggered the start of a camera boom, according to executives at two major video security manufacturers, Clovis, Calif.-based Pelco and Sperry West of San Diego. Falling prices and better equipment quality also played a role.

But it was the Sept. 11, 2001, terrorist attacks, and the London transit bombings last year, that accelerated the demand, particularly from federal, state and local governments. The availability of more than $200 million in federal anti-terror funds helped, as well.

Here are more facts and figures about surveillance cameras in America, by the numbers:

Number of government and private business video cameras in use in America:

Early 2001: .2 million

2006: 5 million

2010: 10 million, projected

U.S. video-security industry annual revenue:

2004: $ 2 billion

2005: $ 9 billion

2010 _ $20 billion, projected

Percentage of market:

Private sector: 60 percent to 70 percent

Government: 30 percent to 40 percent

Costs per camera:

To purchase: From about $2,000 to $60,000, depending on sophistication

Most watched world cities:

London: At least 200,000 cameras

Beijing: At least 263,000, with thousands more to be installed by 2008

(Contact Lisa Hoffman at HoffmanL(at)shns.com)