Ariana Grande, Louis C.K. Concert Rules Push Copyright Limits

Ariana Grande, Louis C.K. and other performers have taken steps recently to restrict concert photography rights and shield jokes—including efforts some attorneys say are unenforceable overreaches.

Grande took heat earlier this year for requiring press photographers to sign over the copyrights to all photos they took at her concerts. Louis C.K. threatened to sue audience members if his jokes are reproduced “in any form.”

The moves are part of a broader trend of performers trying to assert control in the smartphone and social-media era over how what they do on stage—and how much of it—gets to those who didn’t buy ...