That's what happened with RICO. When it was passed they told us racketeering was only organized crime. Now you can get RICO charges doing just about anything.
I'm guessing you're referring to something at the level of discussion of vulnerabilities as opposed to actually breaking into some government resource or an enterprise with enough leverage to affect the nation in some way. Yes, enough lawyer-speak combined with general ignorance could probably make a jury believe any kind of security talk is somehow threatening. I suppose that's where careful wording comes in, for example limiting a threat to include intent to act on at least some specific class of target.
What's to stop them from classifying... say .... computer hacking... as a threat to National Security?