Elon Musk and Twitter Inc. chief Parag Agrawal are butting heads over the way the social media giant handles so-called bots, stoking speculation Musk may try to lower the price or even walk away from his $44 billion offer for the company. Musk told a tech conference in Miami that fake users make up at least 20% of all Twitter accounts, possibly as high as 90%. Twitter disagrees. It reports that spam accounts make up less than 5% of total users, and Agrawal posted a long thread laying out his com