When Freedom and Democracy Interfere with National Safety

This has always bothered me. I am a big proponent of freedom of information, of knowing as much and as many details of what goes on in this country as possible. I wholeheartedly believe this is necessary to keep the country's "movers and shakers" as honest as possible. And even then, as we see daily, even what we do get, isn't enough to prevent some VERY BIG problems.
But where and when do we draw the line on freedom, and all of its components? Many times I've seen, as I'm sure we all have, news stories by investigative reporters exposing weaknesses in our countries security, its defense, its politicians, its morals, its greed. Its discrimination, its lack of unity, its fears, and on and on. One thing I've learned through years of dealing with enemies and other opponents is never let them see or otherwise learn of your weaknesses. Never give them anything to exploit, for exploit they will. And trust me ALL of the United States enemies are watching and listening to our EVERY move, so they can use it against us.
So what is the answer? How do we keep an eye on the corruption and other failings of this country without also letting our enemies see them? I don't know when, where or even if we need to draw a line on our freedoms, but I do know we're tipping our hand to the enemy way too much and way too frequently.