go rogue

phrase

: to begin to behave in an independent or uncontrolled way that is not authorized, normal, or expected

… Clark [a bald eagle] was supposed to fly around the stadium, high above people's heads. But instead, he went rogue and decided to perch on two unsuspecting fans.

—Nicole Gallucci

… the inmates have broken loose and are running rogue throughout the prison.

—Maggie McHale

Anders had been sent to the Amazon to monitor the program's progress under the formidable Dr. Annick Swensen (who may have gone rogue and is no longer returning the company's calls).

—Yvonne Zipp

Whenever a member of a group goes rogue, you can be absolutely certain that other members of that group will pop up with the "bad apple" defense, as in, "Well, sure, there's a few bad apples in every bunch, but that's the exception."

—Christine Flowers