On Monday night, singer Demi Lovato posted a rant on Twitter explaining why she needed to quit that site and Instagram, too. Her accounts haven't been deleted, so it's possible she may be just taking a break. It's unclear what specifically sparked Demi's decision to abandon her social media accounts, but reports speculate it could have been her comments about Mariah Carey and Ariana Grande, which she posted on Instagram and Twitter. The comments didn't go over well with Mariah Carey's dedicated legion of "lambs," and they likely got to her on social media.