I rather liked the line about "Cryptography that post-dates the Fresh Prince." :-)
http://blog.cryptographyengineering.com/2014/08/whats-matter-with-pgp.html
Keybase.io is also a Keybase client, however certain crypto actions (signing and decrypting) are limited to users who store client-encrypted copies of their private keys on the server, an optional feature we didn't mention above. On the website, all crypto is performed in JavaScript, in your browser. Some people have strong feelings about this, for good reason. <https://keybase.io/>If someone else has your private key, it's not very private.
cheers,
Stewart