CCTV-equipped spy cars fetched UK councils as much as £8 million in fines over the last 12 months.
The Smart cars, which feature a 15ft long mast with a periscope-mounted camera on the top, caught around 190,000 motorists making parking and minor driving infringements.
Common infringements by motorists include straying into bus lanes and parking on double yellow lines. But, parents stopping briefly to drop off children at the school gates were also fined.
The Ilford council in North East London said it used a Smart car exclusively to catch careless parents parking riskily outside schools.
According to civil liberties campaign group Big Brother Watch, the Smart cars fetched councils £8,069,714 in fines during the past one-year period ended March 2010. Smart cars earned an average of £187,667 in fines per vehicle.
But, a number of experts have been criticizing the use of Smart cars claiming that they were being used to maximize income rather than promote safety.
Currently, fifty-four CCTV-equipped Smart cars are being used by thirty-one local authorities across the country.