Actually if this went to court it would be a landmark case. Reason being is that artist do not currently have rights to content they upload on social media sites.

You cant copywrite tweets or steal photos uploaded to instagram. If you read your legal information when you sign up you are signing away your rights. Thats why Instagram can use your pictures as they deem. Several artist have sued for images on Twitter, Istagram etc and all of them have never made it to court.

Rights regarding social media are pretty non existence.

We are currently studing this in one of my classes right now. If a decision was made in a case like this it would probably be made by the Supreme Court because it would redefine the law as we know it.