Yes its called revenue raising, have you noticed how the cops will set speed traps on the safest part of the road they NEVER patrol the most dangerous.
i2icho if you elect to take the matter to court you can have it reduced to between 15-30 km over the limit, that way you wont loose your licence.
you can argue that the radar or even laser is not 100% accurate and its less than 4% to have it reduced to the lower charge .
Good luck with whatever you deside to do .
For the rest of you just remember that the cops make mistakes sometimes.....and because they know not many people ( if any ) will challenge they just write the ticket ....
Just have a look at this: http://www.smh.com.au/news/national/a-fine...0823397654.html