Stellar Account ID Search Privacy

Currently when you search for a Stellar Account ID on https://keybase.io it shows the account/person who owns that Stellar Account.

This seems like it could raise privacy concerns. It's very easy to track transactions that are made using Stellar, and being able to resolve account IDs to a person seems like it could lead to unintended privacy concerns.

I'd suggest at a minimum alerting users that their Stellar Account ID is searchable on Keybase and making it clear what privacy implications that has. Even better giving users the option to choose to make their Stellar Account ID searchable on Keybase or not (just like how you currently give users the option to make their emails searchable or not).

Start by reviewing how Keybase currently resolves Stellar Account IDs and how the existing email-searchability option works. Define whether the change should provide an alert, an opt-in search setting, or both, along with the privacy behavior for each choice. Done means the intended visibility and user communication are specified and consistently applied.

Written by the indexing model from the issue text.