Out tennis legend Billie Jean King is the latest celebrity to call for a boycott of hotels owned by the Sultan of Brunei.

On Wednesday, a law that punishes gay sex and adultery by death took effect in the Southeast Asian nation. Hassanal Bolkiah, one of the richest persons in the world, in 2017 celebrated his 50th year as Sultan of Brunei.

“This atrocity begins today in #Brunei,” King said in a tweet. “Please join me and spread the word about the boycott of hotels owned by the Sultan of Brunei.”

Ellen DeGeneres also pleaded with followers to boycott Bolkiah's nine luxury hotels, two of which are located in California.

“Tomorrow, the country of Brunei will start stoning gay people to death,” DeGeneres wrote in a Facebook post. “We need to do something now. Please boycott these hotels owned by the Sultan of Brunei. Raise your voices now. Spread the word. Rise up.”

George Clooney previously wrote an op-ed in support of the boycott and Elton John said that he agreed with the actor.

(Related: George Clooney, Elton John call to boycott Sultan of Brunei's hotels over anti-gay law.)