From Ars Technica:
According to the petition for review filed December 24, 2015 at the District of Columbia Court of Appeals, John Taylor is a "model aircraft hobbyist" who owns "one or more small unmanned hobby aircraft" and intends on acquiring more. He does not describe himself as a drone owner in the brief, nor would he confirm himself as such in a conversation with Ars. However, a profile on DIYDrones.com corresponds to his name and location.
In the case, Taylor asks that the appellate court cancel the new registration system that began on December 21. Taylor argues that the new rule is in violation of Section 336 of the FAA Modernization and Reform Act of 2012, which states that the agency may not create new rules if such model aircraft are "flown strictly for hobby or recreational use." If he is indeed a drone owner, then the suit would seem to turn on whether the courts consider drones and traditional model aircraft as distinct from one another.