One has to wonder if this was actually an accident... 

Via The Register:

London gun owners are asking questions of the Metropolitan Police after the force seemingly handed the addresses of 30,000 firearm and shotgun owners to a direct mail marketing agency for a commercial firm's advertising campaign.

The first any of the affected people knew about the blunder was when the leaflet (pictured below) landed on their doormats in Tuesday's post.

Titled "Protect your firearms and shotguns with Smartwater", the leaflet – which features Met Police logos – advises firearm and shotgun certificate holders to "buy a firearms protection pack at a reduced price" of £8.95.

Smartwater is basically invisible ink. You mark your property using it and if you are burgled, police can use a UV light reader to see who rightfully owns stolen items. The company behind it was formed by an ex-police detective and his industrial chemist brother, and the firm has since forged very close links with a number of UK police forces. Its website boasts of the "traceable liquid's" crime-reducing properties, something that police actively endorse.

The promotional firearms security packs being peddled by Smartwater and the Met appear to be little more than a small can of the "traceable liquid" and the "right to display SmartWater's THIEVES BEWARE® deterrent signage for 5 YEARS", as the product page puts it.

The security implications of the Met distributing home addresses of the capital's 30,000 gun owners (about 5,000 rifle owners and 25,000 shotgun owners) are severe. A large part of firearms security is through obscurity; you take every precaution against strangers learning what your home address is if you store firearms there because that makes you a target for criminals.

It is not clear why firearms and shotguns stamped with serial numbers recorded against the owner's name and address on a police-controlled database need extra marking. Forensic scientists are easily capable of reading a filed-off or altered serial number, two common tricks criminals use in the hope of making their illegally acquired guns untraceable.

Neither is it clear why the Met is helping a commercial advertising campaign. While Smartwater kits are routinely offered to burglary victims by the force, this appears to be the first time it has supplied personal details from its databases to marketers.

Read more here.