But here's the thing ... if you do something you believe is wrong, illegal or immoral, you'll still have to live with yourself. Being human, having empathy (what if you'd lost your confidential papers), being sympathetic and generally operating within the folkways and mores of society serves a purpose. People who can operate without any of these qualities are classified as sociopaths.
So my recommendation isn't to talk to a lawyer, or take any actions related to the papers. Burn them (preferably without reading them) and keep your inward smile. Living with yourself is more enjoyable if you actually like yourself (and find yourself likeable).
EDIT: Posted this at the same time as kefka ... read his response for a real life application of what I've written. And nice to meet you kefka!