Earlier quoted context omitted.
@Keybase users: Check if you uploaded your private key. I hope it is rare but now is the time to make that non existent.
I signed up so long ago that I'm not quite sure what you mean. I remember posting a bunch of public keys (like on my profile here). I think the keybase app generated them along with a private key but it has been like three years. I don't remember at all uploading one or where to find it if I did, can you explain the issue you have in mind a little more?
It's designed to lower the barrier to entry, but is obviously less secure than managing it yourself outside of Keybase (e.g. in GPG keyring, or a physical OpenPGP smartcard such as a Yubikey) - and some consequently wish the storage had never even been offered.