The terms piracy and <answer>theft</answer> are often associated with copyright infringement. The original meaning of piracy is "robbery or illegal violence at sea", but the term has been in use for centuries as a synonym for acts of copyright infringement. Theft, meanwhile, emphasizes the potential commercial harm of infringement to copyright holders. However, copyright is a type of intellectual property, an area of law distinct from that which covers robbery or <answer>theft</answer>, offenses related only to tangible property. Not all copyright infringement results in commercial loss, and the U.S. Supreme Court ruled in 1985 that infringement does not easily equate with <answer>theft</answer>.
In the 1980's, the Supreme Court ruled that infringement does not equal what?
theft