"This is who they say they are" has been pretty reliably implemented in a ton of contexts, can largely be automated, and isn't really novel in any way. Twitter

"This is who they say they are" has been pretty reliably implemented in a ton of contexts, can largely be automated, and isn't really novel in any way. Twitter's blue checkmark is more "this person is notable", which is a different thing and maybe valuable, although I think makes the blue checkmark probably a constant source of frustration for twitter.