My friend Doug Ritter, who runs the excellent disaster preparedness website Equipped to Survive (which I write for on occasion), is also the founder and chairman of Knife Rights, an advocacy group for knife owners akin to what the NRA is for gun owners. ("Knife control," and things like this appear to be the next step in "crime control", so Doug's organization is rather necessary.)
Knife Rights is currently opposing proposed changes in the Federal regulations that would re-classify most of the one-hand opening knife blades sold in this country as "switchblades," and therefore illegal under Federal law. ("Switchblades" are spring loaded and pop open at the push of a button or release of a slide.) Since many State laws follow the Feds in this case, they would become illegal in a number of States well.
One-handed opening blades are very popular these days - most hunters and fisherman you see have one, and almost every person working in the electrical and IT fields, or in construction, sports one on their belt or clippped in their pocket. Most of the popular "multi-tools" sold in the US (including my Leatherman Charge) have such blades. All of these would become illegal if these rules changes take effect.
The issue has been noticed by Davil Kopel at Volokh Conspiracy and over at Instapundit. If you oppose these changes, write your elected representatives. And, join Kinfe Rights.