Seen as an unnecessary burden by some and a smart safety measure by others, the US government's mandatory drone registry certainly had the desired effect. Hundreds of thousands of hobbyists have now registered their devices with the Federal Aviation Administration (FAA). As it turns out, however, the whole thing wasn't well, entirely legal, with an appeals court today striking down the rule and leaving the registry seemingly dead in the water.

Introduced in 2015, the mandatory drone registry required owners of unmanned aircraft weighing between 0.55 and 55 lb (250 g and 25 kg) to register their machines with the FAA. If not, they faced fines of up to $250,000.

This drew the ire of some in the drone industry, and the many hobbyists who had been flying small aircraft recreationally for years. One such hobbyist, John Taylor, went to the lengths of challenging the FAA's new rule in the US Court of Appeals. Today, that court ruled in his favor.

"Taylor is right," the decision reads. "In 2012, Congress passed and President Obama signed the FAA Modernization and Reform Act. Section 336(a) of that Act states that the FAA 'may not promulgate any rule or regulation regarding a model aircraft' ... The FAA's 2015 Registration Rule, which applies to model aircraft, directly violates that clear statutory prohibition. We therefore grant Taylor's petition and vacate the Registration Rule to the extent it applies to model aircraft."

The decision doesn't change the rules around flying drones for commercial reasons which were implemented last August and still require mandatory registration. The FAA released a statement this afternoon addressing the decision.

"We are carefully reviewing the US Court of Appeals decision as it relates to drone registrations," it reads. "The FAA put registration and operational regulations in place to ensure that drones are operated in a way that is safe and does not pose security and privacy threats. We are in the process of considering our options and response to the decision."