GARDAI catch criminals. Doctors treat patients. And the Revenue collects taxes.
So, to some extent, it is no surprise that Revenue sees the property tax database as another weapon in its arsenal to pursue tax dodgers.
It is simply far too tempting for any taxperson to ignore (we say that because the Revenue's boss, Josephine Feehily, is not happy with the media's habit of constantly referring to the 'taxman').
It contains the names and addresses of the owners of 1.6 million houses – as well as details on hundreds of thousands of other homeowners who are exempt from the property tax.
And it has the potential to become the Revenue's most lucrative source of information since it got access to the names of the Ansbacher account holders back in the 1990s.
Compliant taxpayers should have nothing to fear. And they certainly will not be complaining if the Revenue's computer system manages to detect criminals who have bought multiple houses using ill-gotten gains but claim to be earning peanuts.
The Revenue has already demonstrated a hard-headed attitude to collecting the property tax. A TD recently raised a case in the Dail about a woman in the south-east who had died after signing up to pay her €112 property tax. She had opted to pay by direct debit but two payments worth a total of €37 were left outstanding due to her death.
The Revenue has confirmed that the debt will now pass on to the woman's estate to settle.
In the new year, it will be deducting €200 from the wages or social welfare payments of those who have not paid the €100 household charge.
And it will start analysing property tax records to see which taxpayers have undervalued their houses relative to their neighbours' or property sales records.
There have been complaints for years that the State had been paying over €500m per year in rent to private landlords without being fully sure they were tax compliant.
The system has been tightened up with PPS numbers now required, but the use of the property tax database should track down any remaining tax-evading landlords.
The system the Revenue is using to analyse the property tax data is known as Risk Evaluation Analysis and Profiling. It may well reap a bountiful harvest for the Revenue and ultimately the compliant taxpayer.