Here's the deal. Most classified information is segmented. Say I want to build a encrypting radio. I may have one team build the encrypting part, but they don't know it is for a radio. I have a second team build a radio, but they don't know an encrypting part is going in it (there is just a spec for a 'device' to be plugged in). If I am in the radio building team, and the encrypting info is leaked, and I read it, suddenly I know that an encrypting radio is being built, something that the average person reading the leaked info wouldn't know.

You don't access classified material that you are not cleared for. Period.