I find it amazing that a single person wants to defend the practice described in the OP.
It's none of their business.
It's the email password part that really upsets me. That's like asking someone for the key to their mail box. Especially with the amount of online banking and shopping that people do today. It's not unusual for a person to have credit card statements, bank statements and other identity based information in their email box. This is information that a police officer would need a warrant to acquire!
Not yet, but it's up to the interviewer to decide if you *are* to become part of their business...
...You know because I'm just curious if there are any boundaries that could be crossed.
Except that this has already been refuted, that sharing specific information with one company doesn't mean you should be expected to share this same information with another company... *facepalm*
I can't believe people actually tell others their real names anytime!
Corporations ship jobs overseas because we (as a society) want them to.
You know because I'm just curious if there are any boundaries that could be crossed.

Not yet, but it's up to the interviewer to decide if you *are* to become part of their business...
And, your point? Would you comply if they asked for the key to your house? The key to your car? Your storage locker?
I understand, but were talking about Facebook here, not your medical records. At least I should hope not...
It's not forfeiting privacy rights, only including one more company in this particular private circle.
I'm still amused here about how touchy people are about releasing what they post on Facebook (everyone I know only puts stuff they'd love to show to anyone there). Is it mostly younger people who assume Facebook is truly private?
Of course there are boundaries. My point is that if it comes from your "private" Facebook page then it has already been shared with one company. If you have stuff there you don't want to share, it's a little late.
You're giving them your PASSWORD!!!!!
How many people have such a poor memory, that their facebook password is the same as EVERY password they have? Everything from bank records to online games would be available to the prospective employer.
Honestly, if you think that's no big deal, you're out of your mind.