According to CoinMeta, Vitalik Buterin indicates that exploring registration-free options for Signal helps to reduce reliance on phone number systems, lower the risk of SIM card exchanges, and increase the difficulty for governments to implement bans. He pointed out that this measure does not yet achieve true anonymity, as message metadata can still be used for identity association. He believes that the only form of privacy that is justifiable is when each message cannot be linked to others, and this direction is being explored by projects such as Session and Simplex. Protecting against spam and denial-of-service attacks is the next focus.