There are plenty of security plays these days

Q: Is there a way to invest in technology companies that profit from the increased demand for surveillance, weapon detection and security cameras?

A: Ever since the terrorist attacks rocked the nation, companies, institutions and individuals have looked at surveillance very differently.

Security has been beefed up most obviously in airports, but also in office buildings, day care centers and in some homes. This increased awareness of security was a popular theme for investors immediately after the terrorist attacks. USA TODAY in 2001 pointed out how investors almost immediately surged into shares of security stocks.

The story also gives investors a few clues about the industry and the players. The first company mentioned, InVision Technologies, makes baggage scanners used by airports. It was bought by General Electric and is now GE InVision Technologies. Siemens, a German company that trades by the symbol si on the New York Stock Exchange, also has interests in security.

Other companies mentioned in that USA TODAY story include L-3 Communications lll, which provides surveillance and security products, primarily for defense.

There are several others, though, in the industry. Axsys Technologies axys makes camera systems used in all sorts of security devices used by government, defense, businesses and homeland security. Nice Systems nice makes digital recording systems, which may have security uses. Magal Security Systems mags specializes technology to help monitor and control who gets in and out of the perimeter of a building or land.

Security cameras aren't always the pricey ones you see perched in office lobbies. Computer peripheral maker Logitech logi and Microsoft msft both make "webcams," which are small cameras you can attach to a PC. Some use these cameras to watch their homes remotely or to check in on a nanny. And some networking gear makers, including the Linksys unit of Cisco Systems csco make cameras that attach to corporate or home networks.

Matt Krantz is a financial markets reporter at USA TODAY and author of Investing Online for Dummies. He answers a different reader question every weekday in his Ask Matt column at To submit a question, e-mail Matt at Click here to see previous Ask Matt columns.