Their approach to wanting the information would be that if you are an employee of the state (the public), they may want to make sure you don't have any publicly available information that may tarnish them.
As for passwords, that is the area of concern...and I would think that contravenes privacy as it clearly leaves you open to identity fraud.
I had to be checked by the Federal Government here once before I could work on a security project and yes, one aspect was I did have to disclose all my email account information. But not passwords. I would think anything to do with disclosing identity is only enforcable at a federal level to that degree. I mean fuck, they can't search your house without a warrant!