Three sources have told The Washington Post that Elon Musk’s bid to buy Twitter is on the rocks. According to the newspaper, Musk demanded Twitter provide data to back up its claim that spam accounts make up less than five percent of users—but Musk’s team now says it can’t verify the data that was provided. The sources say Musk and his associates have also cooled on certain conversations related to funding the $44 billion deal. Should Musk try to end the landmark takeover, a legal battle is likely. Under the terms of the deal, Musk must pony up $1 billion just to pull out but legal experts say Twitter may try to force him to follow through with a purchase if his rationale for backing out is unrelated to what the Post calls the “company’s fundamental business.” Of the ongoing saga of negotiations, one source said that “Twitter has not been cooperative.”