Denmark has a system like this, MitID, it support OAuth2 and OpenID Connect, so here it should be possible. The US doesn't have a country wide system for identi

Denmark has a system like this, MitID, it support OAuth2 and OpenID Connect, so here it should be possible. The US doesn't have a country wide system for identification only, not that I know of at least. I can understand companies, like PornHub, not wanting to pay along, unless the government provides a system for age verification. Still it would also be a lot of work to integrate with every single government ID scheme around the world. Also they normally aren't free to use, each query normally cost money, why would the porn sites want to pay for a service they didn't want anyway. Another issue with these system: They are high value target and they tend to be just as crashy as other government IT projects.