If you had no idea it was classified before you distributed it, you probably wouldn't have broken any laws. Given the way classified documents are labeled, tha

If you had no idea it was classified before you distributed it, you probably wouldn't have broken any laws. Given the way classified documents are labeled, that's an incredibly unlikely scenario: classified documents are marked with the classification level on every page and paragraph (individual paragraphs may be classified at a lower level than the overall document), and have cover sheets explaining exactly what the classification level means, which includes a statement warning the reader that anyone can be prosecuted for unauthorized distribution, not just people who have agreed to protect it. So your understanding is wrong: the prohibition extends to everyone. There are also directions for what to do with it if you aren't supposed to have it (e.g. "Return to nearest office of [appropriate federal department or agency].") If the hypothetical piece of paper on the street were a single page marked with a classification level, but without the cover sheet and its explanation, you might be able to argue that you didn't think that you were legally prohibited from distributing that information. Then again, "I didn't know that was illegal, your honor," generally doesn't play well in the courts. IANAL, so I can't tell you what would happen in this situation, but I can tell you that even if you were to avoid conviction the overall experience would probably be time consuming, expensive, and generally unpleasant.