@david @tedcurran

Say I wanted to follow your content and you are posting both micro blog posts through one program and videos through another. I could use your certificate to follow you and know that both the microblogs and the videos are actually coming from the same identity even if they are coming from different instances.

It's not about proving who you are as a person.
It's about your being able to brand your content across platforms, if you want to put it like that.