An anonymous reader writes: Twitter has updated their site rules to prohibit "behavior intended to harass, intimidate, or use fear to silence another user's voice." According to the new rules, "You may not promote violence against or directly attack or threaten other people on the basis of race, ethnicity, national origin, sexual orientation, gender, gender identity, religious affiliation, age, disability or disease." This follows criticism that Twitter (and other social networks) haven't done enough to prevent the ramblings of the Islamic State and other terrorist groups. "Tuesday's announcement did not disclose changes to Twitter's enforcement strategy. A company spokesman declined to say if any were in the works. The new rules also said that Twitter might respond to reports that somebody is considering 'self-harm' by contacting the person to express concern and provide contact information to mental health practitioners."