It has long been established that you had to register a copyright before you could file an infringement lawsuit, but some courts had accepted merely filing the paperwork with the Register of Copyrights as being enough.
Now the USSC has ruled that a copyright holder must complete the registration before they can sue.
From The Hollywood Reporter:
The U.S. Supreme Court unanimously ruled on Monday that copyright owners must wait for registration before pursuing infringement claims in court. The decision settles a circuit split wherein certain courts had previously held that merely applying for registration was enough to satisfy the statutory prerequisite for a lawsuit.
The opinion in Fourth Estate Public Benefit Corporation v. Wall-Street.com may influence the range and number of copyright lawsuits in the entertainment and media industry. In this case, Fourth Estate licensed its journalism works to Wall-Street.com before the agreement was canceled. When articles weren't removed from the website, Fourth Estate filed suit, leading to a challenge over whether the plaintiff needed to wait until the Register of Copyrights either accepted or refused the application for registration.
Pundits disagreed on which standard was the right one. Public Knowledge argued there was a reason why Congress required registration before litigation; this guaranteed a comprehensive public record of ownership of copyrighted works.
The Authors Guild, on the other hand, held the position that merely filing the application was sufficient. Anything else would amount to a delay which The Authors Guild claimed would have massive impact on an author's ability to protect their work. The major record labels agreed, pointing out that it was imperative that administrative delay not impair anyone's attempt to seek redress against infringers.