For anyone interested...there's some amusing pics of GATSOs which have their best days behind them:
http://www.speedcam.co.uk/gatso2.htm
Fire...paint....air rifles...hitting them with lorries & JCBs...all tools to stop the GATSO getting ya'
page 4 of that link even has fake GATSOs....NIMBYs who put up fake boxes either in their gardens or on telegraph poles to mess with drivers...when even the police don't want/need them there