In the San Francisco Bay area, law-breaking motorists have to worry not only about red-light cameras taking pictures of their illegal behavior but also about fellow drivers doing the same. A pair of local commuters has set up a Web site to display digital photographs of scofflaws driving solo in car pool lanes or violating other traffic and parking laws.

Sean McIntyre, who shoots photos and helps maintain the site, www.carpoolcheats.org, says the project was inspired by the experience of being tailgated at high speeds by a driver who didn't belong in the car pool lane to begin with. "That's why we did it originally, to vent our own frustration," he says.

When McIntyre and his partner spot cheaters, they pull into another lane to take pictures of the driver and the car's license plate. McIntyre adds that it helps "to relieve the boredom" during a 100-mile commute from California's Central Valley to San Jose. But he says he's received lots of e-mail messages from people who are supportive of the idea of embarrassing violators in hopes of changing their behavior.

It's not a technique the authorities are likely to embrace, however. Mike Wright, a California Highway Patrol spokesman, says that cheating in car pool or HOV lanes is inevitable and that studies have shown there aren't enough violators to reduce the effectiveness of the lanes.

A bigger danger, he says, is the possibility that McIntyre and his buddy might provoke a violent incident. One driver, whom the Web site calls the "Carpool Cheater Poster Boy," flipped them the bird and threw a ceramic mug at their car. "We want to curtail any type of confrontational activity on the highways," Wright says.