Mozilla has refused to axe a Firefox add-on that the government says helps users bypass domain name seizures.

MafiaaFire Redirector is an automated tool that works a little like a mail forwarding service but for domain names. It hooks up to a central database that tracks when a site moves from one domain name to another, meaning users can type in the original address and still get to the intended site.

The developers of the add-on, who are independent from Mozilla, are open about the way this is designed to be used: it’s for when domain names have been seized by officials — specifically when, in the opinion of the developers at least, such a seizure was illegal.

They give the example of a torrent search site whose domain name was taken down by ICE (US Immigrations and Customs Enforcement) through a seizure warrant, despite the fact that no illegal content was hosted on the site itself.

Mozilla says it has now received a Department of Homeland Security request to remove the add-on from its official “market.” According to Mozilla it has a policy of complying with court orders and warrants, but there’s no such order in this case.

As a result it’s taking no action unless and until the DHS explains whether the request has any legal force and whether there’s any court ruling to say MafiaaFire itself breaks any laws.

Arstechnica notes officials may be onto a losing battle: not only is a Chrome version of MafiaaFire on the way, but the code has been open sourced, meaning there’s nothing to stop a cat-and-mouse game with new plug-ins being produced.