In the 2005 "Grokster" decision, the Supreme Court ruled unanimously that file sharing networks could be held liable for copyright infringement if they take "affirmative steps" to encourage infringement.
Grokster closed down as a result, and the recording industry pretty much assumed it had won that battle.
There is no arguing that the file-sharing landscape changed for good when the RIAA managed to 
If you’re residing in Antarctica, chances are you are an employee of the United States Antarctic Program (USAP).