I first started using @KeybaseIO a few years ago to link together my social accounts. This creates a web of accounts which is dramatically more difficult to impersonate than any single account. So, it's an exercise in impeding identity theft.
A web of accounts could, for example, enable me to trust your email signature when I only know you through Twitter.
The Keybase filesystem is one of the newer tools and has a lot of promise. It is a global namespace with public and private trees. The private tree allows any two parties have a truly confidential exchange of data just by reading and writing in the special folders on their computer. You can look over here for more info about it.
This web page is actually hosted in the kbfs at
/keybase/public/kourier. The content is signed during upload and so is verifiable by running the Keybase app on your computer, though it is not obvious in your web browser.
If you install Keybase you'll be able to passively track changes in the web of identity with commands like
keybase follow kourier