https://www.vice.com/en_us/article/7x54md/twitter-is-asking-sex-workers-if-theyre-bots-and-demanding-their-phone-numbers

Sex is allowed on Twitter. It's right there in the terms of use. "Sensitive content" like sex and nudity is allowed, as long as it's not featured in the header image of your profile or your profile picture.

But after another spate of sex worker Twitter accounts being limited or locked, users who rely on social media to connect with fans and others in the community are once again reminded that they're at the mercy of big tech platforms. Motherboard has seen at least a dozen sex workers complain that they've been locked out, or were forced to verify phone numbers to continue using their accounts.