Dozens of home addresses of gun owners have been easily obtained in a simple privacy blunder that a veteran police officer fears may be utilised by thieves.

The treasure trove of addresses has been discovered by simple online searches of publicly available information. .

Some of the firearms featured in ads that could be used by gun thieves.

It has prompted a warning from NSW Police's Firearms Squad to "use common sense when providing personal details in conjunction with information about firearms".

A gun owner and veteran police officer, who did not want to be identified, alerted researchers to his findings and a list of about 30 home addresses was passed on to law enforcement to show how much information gun owners were unwittingly revealing.