Big cheeses at the Mozzarella Foundation have delivered a Gorgonzola flavoured raspberry to the government spyware outfit Gamma International.
The open source browser maker was furious after it was revealed that Gamma was using Firefox as a disguise for its FinSpy software.
FinSpy is used by governments to snoop on citizens and the product was outed by human rights group Citizen Lab.
Mozilla has sent Gamma a cease and desist letter today demanding that these illegal practices stop immediately.
Writing in its blog, a spokesMozilla said that not was the activity illegal, but the company take them seriously because they are deceptive, harm users, cause consumer confusion, and harm Mozilla's reputation.
"We cannot abide a software company using our name to disguise online surveillance tools that can be – and in several cases actually have been – used by Gamma's customers to violate citizens' human rights and online privacy," the blog said.
FinSpy did not affect Firefox itself or the way the browser operated and only uses the brand and trademarks to lie and mislead as one of its methods for avoiding detection and deletion.
When a computer user targeted by FinSpy looks at files related to the snooper, Gamma misrepresents its program as being 'Firefox.exe' and includes the properties associated with Firefox along with a version number and copyright and trademark claims attributed to Firefox and Mozilla Developers.
The tactic turned up in a spyware attack in Bahrain that targeted democracy activists and in spyware used in the run-up to Malaysia's upcoming elections.