With barely any time to cool his heels following the massive legal effort that released pop star Britney Spears from her restrictive 13-year conservatorship, Hollywood’s “go-to” litigator Mathew Rosengart has joined the team fighting to free another legendary artist. Peter Max, 84, is famous for having helped refurbish the Statue of Liberty and creating art with a psychedelic, pop-art style. Now, his daughter says, he is trapped in a “predatory” guardianship comparable to prison.

Libra Max claims her father is trapped in his Upper West Side apartment, with family members restricted to hour-long visits with permission from his guardians. She alleges that they have taken his phone and pets away, and bill his estate hundreds of thousands of dollars annually. The guardianship, Max’s daughter contends, has “isolated him, medicated him, and stripped him of his civil liberties.”

“I am honored to join the team’s laudable efforts to seek justice for Peter Max,” Rosengart said in a statement. “This typifies the type of guardianship that merits judicial attention and potential state and federal legislation.” The lawyer, referred to by Spears’ fans as ‘Rosen-god,’ will continue his work on the star’s case as she fights her father and the former manager of her estate.