can i supply more than one so sites could check if one of the providers has been compromised or something similar? does it make sense to have more than one?
As I understand it, it checks with the domain from the 'email address' to verify you. (air quotes because it needn't be possible to send email to the identifier). So it wouldn't make sense to have more than one way to verify one ID. If the site you're signing into is particularly sensitive, it could require a separate check - perhaps even a second BrowserID login from a different domain.
