When you sign into Bank of America on a computer you haven't used with them before, the site prompts you to answer one of your security questions.
How exactly does this make the site more secure?
Is the assumption that if a person somehow guessed your password, they couldn't get in on their computer because they wouldn't know your security questions? If they have your password, they've already won. It seems like all this does is make it harder for legitimate users to use the site...
Based on the answer from @AJHenderson it seems that the scenario we're trying to protect the user from is a key logger. Perhaps we're counting on the key logger as having been placed after the user already marked this computer as "trusted" by entering their security question? In that particular case the hacker wouldn't have captured the user's security question answer. Wouldn't a better solution be to have the user enter a PIN via an onscreen key pad that wouldn't be so easily key logged?