Excerpt: Eliot Spitzer, the New York state attorney general (below), has brought big companies to heel. But his probes will have consequences for little guys, too. That's because his investigations have underscored the idea that employers have a fiduciary responsibility to ensure that employees are not overcharged for benefits. If your 401(k) provider or insurance company overcharges your workers, you may be liable. This news has set the staid benefits-administration world abuzz.