I'm not a lawyer, but my guess is that if you could get a request like this in writing, the right lawyer would be able to get you a hefty settlement under existing law. Just guessing, but I'd be surprised if it's legal to ask prospective employees to engage in unlawful activities as a condition of employment. As mentioned before, sharing your Facebook password is illegal.
I'm certain that anyone asking to snoop through your Facbook knows they are doing something "wrong" - maybe they don't understand the full implications, but I'm sure none of them would be stupid enough to put the request in writing.
Anticipate the next time the boss "reminds" you to give him your password, and have your phone recording when it happens.
In many US states, it is legal to record a conversation if one of the parties is aware (i.e. if you are recording a conversation in which you are a participant).
I'm uncomfortable with doing this in normal circumstances, since it's a pretty manipulative way of getting a recording of someone. But if you're getting abusive requests from your employer and (I agree) you're not likely to get it in writing, this seems like the appropriate response.
There was a thread here on HN some time ago, where someone argued that it's illegal anyway, because of some misguided law that makes it a federal crime to violate an internet company's TOS. I can't find that thread right now, though.
That would be the Computer Fraud and Abuse Act[0,1]. The relevant bit is "Whoever ... intentionally accesses a computer without authorization or exceeds authorized access, and thereby obtains ... information from any protected computer ... shall be punished as provided in subsection (c) of this section." A "protected computer", by the way, is any computer "which is used in or affecting interstate or foreign commerce or communication."
That's not relevant, though, because US v. Lori Drew[2] decided that a user can't be prosecuted under the CFAA for breaking a ToS agreement. (BTW, IANAL.)
Which the prosecution used against Lori Drew, and ultimately failed. The hysteria about it being illegal to violate TOS was a feature of the original verdict against her, which was set aside on acquittal. It's a (now) non-story.
