Two traditionally distinct realms of security?the physical world with guards, swipe cards and security cameras, and the virtual world dominated by firewalls, passwords and cryptography?are quickly meshing in the post-Sept. 11 environment. Expect new Mission: Impossible-like systems that scan retinas, but also plan on everyday technologies getting spiffed up, integrated and Web-enabled. For example, a company called WebEyeAlert, in Chelmsford, Mass., has built software that links closed-circuit TV (CCTV) surveillance systems to the Web. WEA is a division of Biscom, a fax server company. Fax servers are built around digital imaging technology, so Biscom simply applied its patents to the world of surveillance imaging. The WebEyeAlert DVR system enhances existing CCTV by allowing anyone with properly authorized access and a browser to control the cameras?zoom, tilt, pan and so forth?remotely from a computer. The software also recognizes movement in the picture and can send out alerts if a specified level of movement is crossed.These systems are already being used to proactively prevent school violence. The high school in Londonderry, N.H., installed a $77,000 WEA system with 48 cameras (and 16 more planned) in the school\u2019s common areas. Chuck Zappala, who heads the project, can check out what\u2019s going on in the middle of the night from his home and has given specific rights to police and fire patrols to access the cameras from the outside of the building in case of fire or other emergency. Determining who will control the unified physical and virtual security is one of the remaining challenges.Unfortunately, what prompted Zappala to buy the system was a raft of threats?eight in two weeks including some bomb threats at the school. The school shut down for two days and reopened with an atmosphere hardly conducive to learning, as police used metal detectors to conduct searches. Since the system was installed, two threats were squelched without anyone having to enter the building. "It\u2019s working incredibly well," Zappala says. "In one case we were able to dismiss the threat, and in another we located students we felt were involved." As an added boon, graffiti has all but disappeared, Zappala says.