That was the way it was on February 19, 2016, when the FAA ruled that all model aircraft weighing greater than 7 ounces (250 grams for our metric folks) and less than 55 pounds required registration. According the FAA, existing model aircraft (e.g., fixed wing, helicopter, multicopter, gliders, etc.) had to be registered prior to its first outdoor flight. Once the pilot was registered, the same registration number was to be used for all of his/her models.
Lucky for model aircraft enthusists, John Taylor took the FAA to court and the court ruled that section 336 of the FAA Modernization and Reform Act of 2012 expressly prohibits any further regulation, including registration, of model aircraft. Now your butterdrone may fly free. Good luck getting your $5 registration fee back! Actually, go here to get off the drone registery and get your $5 back!
There is still a chance that Congress could eliminate section 336 when the FAA Modernization and Reform Act goes back for reauthorization. Now is the time to contact your Congressman to let your views be known.
And, if you happen to run into John Taylor, buy him a beer.