The jurors also found MP3tunes was willfully blind to copyright infringement on its website. They will now decide how much in damages should be awarded.
Founded in 2005, MP3tunes offered a cloud music service that allowed users to store music in online lockers.
When initially launched, the lawsuit was closely watched as a barometer for how courts might view cloud-based music storage services.However, much has changed with the companies since the lawsuit was filed. EMI has been split up, its recording music business acquired by Vivendi SA's Universal Music Group and a consortium led by Sony acquiring its publishing arm in 2012.
The case is Capital Records Inc et al v. MP3tunes LLC et al, U.S. District Court, Southern District of New York, No. 07-09931.