It's against the TOS for the user to let another access their account via the password. I didn't see anything in there about being on the receiving end. I would say it's implied, but it's not explicit. So security would be effectively forcing the user to violate the agreement with Facebook. Not sure how that plays out legally, but I'm assuming Facebook has every right to terminate their account for complying with the security check.
Here's the clause:
"You will not share your password (or in the case of developers, your secret key), let anyone else access your account, or do anything else that might jeopardize the security of your account.
You will not transfer your account (including any Page or application you administer) to anyone without first getting our written permission."