Indicate whether a user has uploaded his private-key

I would like to propose a feature to indicate whether a keybase user uploaded his private-key to keybase.

I understand the people that are complaining about the possibility to upload a private-key and I understand your desire to provide certain features that require an uploaded private-key.
I think an indicator for "potential insecure" keys would be a good compromise.

The issue does not name any files, tests, or entry points. Start by reviewing the four existing comments and identifying which Keybase client, installer, or website surface should show the indicator. Done would require an agreed scope and a defined, trustworthy way to communicate whether a private key was uploaded.

Written by the indexing model from the issue text.