The example in the news item is cited mainly to show______.

Nowadays in towns and cities across America, patrol cars are deployed elsewhere because unattended, fixed cameras are nabbing speeders in record numbers.
    The cameras record the speed limit in the area, how fast the vehicle is going, and the date and time of. the offense. And they snap a close-up digital image of the vehicle’s license plate as it whizzes past.
    And these cameras are lucrative sources of revenue for cash-strapped communities. For example, last year alone, fines paid by drivers caught by speed cameras in a county outside Washington, D. C., brought in more than 13 million dollars.
    Police chiefs laud the cameras as life-savers. According to Washington’s chief, Cathy Lanier, traffic deaths in the city have been cut in half in four years. "We see fewer high-speed crashes," she said. "And because of speed enforcement, when people do crash, it’s at a slower speed, so there are less likely to be fatalities."
    But opposition to speed cameras is fierce and loud. People across the country argue that the devices are just money makers and that time spent processing images, sending out tickets, and collecting fines pulls police away from crime-fighting.
    Besides, the critics argue, habitual speeders quickly learn where cameras are mounted. They slow to the speed limit when passing them, then resume their reckless ways.