And the people benefitting are motorists in the NSW Hunter Valley.

Whenever he has a spare few hours, Mr Dimarzo, from the Maitland suburb of Rutherford, puts out a call on Facebook for the location of any stationary speed camera cars.

What he does next is simple. And legal.

He parks up behind the stationary camera car and warn motorists with a cardboard sign of the camera's presence.

He's received plenty of applause on social media and cheers from passing motorists. Others take the time to stop, hand him a beer and congratulate him on his gutsy effort.

"These cameras are just 100 per cent revenue raising," Mr Dimarzo said.

"They're supposed to be set up in black spots - which they never are - and drivers are being hard done by."

Inspector Dan Skelly of Port Stephens/Hunter Police District said Mr Dimarzo is not necessarily breaking the law but said there were obvious safety issues that must be taken into consideration, particularly if he is an higher speed area like an 80km/h zone.

"He needs to be in a safe area," Insp Skelly said.

He said police would also need to ensure that derogatory or profane language hasn't been used on his signage.

"Police would also need to attend to check on his welfare and the welfare of the person in the camera car to make sure neither are being abused. Police would certainly not be encouraging other people to do as this gentleman is," Insp Skelly said.

Mr Dimarzo's quest started during COVID lockdown when he began reading up on laws surrounding stationary speed cameras.

"I joined a group called Know Your Rights and I have learnt so much about what can and can't be done in terms of fines," he said.

He said police officers have tried to move him on a couple of times but he has never been fined: "And that's because what I am doing is totally legal."

"I'm not out here doing this for hours on end for fame or fortune - I just want people to slow down, do the speed limit and be aware of their rights," Mr Dimarzo said.