It would've been nice if OpenID provided a way for Web sites to contact users without knowing their email address. This way, the Web site owner will not to put

It would've been nice if OpenID provided a way for Web sites to contact users without knowing their email address. This way, the Web site owner will not to put up an annoying page asking for an email address, and the user has control over who's allowed to contact them through their settings with their OpenID provider. Facebook is hopeing to be such provider and they're giving these nice features. There are a few Web sites that allow you to login to using your Facebook cridentials, and by doing so they can email you without knowing your email address. And, Facebook allows you to optout at any time and they also measure how many people opt out and put a cap on the offending Web sites if they start to spam people. It's a nice system, except for the vendor lockin part.