The police action in fining for just one km over the speed limit is
challengeable.
If your speedo has a top calibration mark of 200Km/hr and the accuracy
is stated to be 1% then any speed between say 58 and 62 km/hr is legal.
Likewise any speed between 98 and 102 km/hr is legal.

You see, instruments are calibrated as a percentage of full scale deflection.
Now, I have not been able to ascertain what the Australian design rules
actually specify.
Likewise, the instrument used by the police has a similar accuracy
specification and if charged you should ask for the calibration
certificate and check the accuracy of the instrument and if the
if the calibration date is within specs.
The full scale deflection of the police instrument could be 300 or
500 km/hr, who knows, the court procecutor would have to supply that info.
So if FSD was 500km/hr and accuracy was .5% then any speed between
97.5km/hr and 102.5 km/hr is legal.
Remember errors would have to be assumed to be additive in your favour.
So anything between 95.5 and 104.5 km/hr indicated on the
police instrument would be legal.
This is why there has always been a tolerance level.
There is also the matter of tyre pressure.

Under the Federal Weights and Measures laws any monetary charge made
using a measuring device has to comply with the calibration equirements
so a certificate has to be available on demand.
Same applies in the local green grocers.

If you speed you are breaking the law
If you flash you lights you are breaking the law
Ironically you can stand on the side of the road holding a warning sign and that is not illegal.
I think both of the above deserve the full wrath of the law and Yes there is a lot of legitimate revenue to be made for government while they are at it.

Surely, as speeding is breaking the law and it is the duty of citizens to uphold the law then said citizens should not speed and they should encourage others to similarly uphold the law.

I maintain that it is also a citizen's duty to stop others from breaking the law, if possible, therefore warning fellow motorists to slow down is part of our civic duties.

It is the traffic authorities statement that there will be no tolerance
that is the problem.
There just is a tolerance built in as soon as you use measuring
instruments and the law and the courts CANNOT change that.

<< Surely, as speeding is breaking the law and it is the duty of citizens to uphold the law then said citizens should not speed and they should encourage others to similarly uphold the law. >>

Yes but there is the law and there is the law! One is the official law and the other is the real-world law. If you observe the official road rules and expect others to do the same and get angry when they don’t, then you’ll run into conflict all the time.

If you observe the real-world laws, you’ll find more peace of mind, and you’ll be driving in a safer manner.

Just noticed on the ABC News that a section of the Stuart Highway in the NT has had all speed limits removed, once you pass the De-restricted sign the limit is how fast your car will go.

Note that the sign is a black bar diagonally across a white disc.

The same sign is used in NSW and DOES NOT mean that the limit is greater than 100kph.

So, if you come across one of these signs don't get carried away.