The tool is nearly ready to be released, Zuckerman told Ars, but the University of Massachusetts Amherst associate professor is afraid that Facebook owner Meta might threaten legal action if he goes ahead. And his fears appear well-founded. In 2021, Meta sent a cease-and-desist letter to the creator of the original Unfollow Everything, Louis Barclay, leading that developer to shut down his tool after thousands of Facebook users had eagerly downloaded it.

Zuckerman is suing Meta, asking a US district court in California to invalidate Meta’s past arguments against developers like Barclay and rule that Meta would have no grounds to sue if he released his tool.