The beginning of the end for #bitcoin? Maybe, on social media: Twitter is drafting a policy on ads for the volatile cryptocurrency and others like it after bans by competitors Facebook and Google, according to a person familiar with the matter.

Twitter hasn’t finalized its policy yet, the person said Monday. Facebook, based in Menlo Park, Calif., prohibits ads for financial products frequently associated with fraud, including cryptocurrency and initial coin offerings, while Mountain View, Calif.-based Google says it will block promotions for cryptocurrency and related products including trading advice starting this June.