According to 'U.S. May Require Fingerprinting and Study of Rocket Hobbyists':

Hobbyists who build and launch high-powered model rockets could soon be subject to background checks, fingerprinting and storage inspections.

Under new provisions set to go into effect May 24 under the Homeland Security Act, the Bureau of Alcohol, Tobacco, Firearms and Explosives would place further restrictions on the fuel that powers the rockets...

The new rules will require buyers of the rocket fuel ammonium perchlorate composite propellant to submit their fingerprints and photographs to the bureau. The government will check applicants' backgrounds to see if they are among those banned from possessing explosives, felons, for example.

Under the proposed rules, the government will also inspect the areas where permit holders store explosives at least once every three years.

Hobbyists have won the support of Senator Michael B. Enzi, Republican of Wyoming, who is drafting legislation to free rocketeers from the rules.

Aw, who cares? It's just a bunch of nerds, right? First they came for the model rocketeers, and I didn't care because I wasn't a model rocketeer. Then, they came for the chess club members, and I didn't care because I was actually concerned about bishops, kings, and queens being whittled down into deadly weapons.

Anyways, if you're concerned about the slippery slope aspect of this attempt to tradeoff security for freedom, consider contacting your elected representatives. There's more information at the Amateur Rocketry Society of America and National Association of Rocketry sites, and there's background information on rocketry here.