> It uses phone numbers because phones already have contact lists, stored clientside, keyed by those numbers. This makes sense for contact discovery, which is

> It uses phone numbers because phones already have contact lists, stored clientside, keyed by those numbers. This makes sense for contact discovery, which is important for normal people who just want a chat app that works. But there are a very important segment of signal users, people with an elevated threat model, who I would be willing to bet a good portion of them would gladly sacrifice contact lists if it meant not having to share their phone number.