150 years ago private citizens in the UK formed local rifle clubs
to help defend the UK, which eventually became the Territorial Army*
Alas these days, I fear that any attempts, or even declared interest, in doing something similar or assisting these excercises would not go down well with the powers that be. Certainly I don't seem them appreciating efforts along the lines of Gary McKinnon exposing security weaknesses.
I only hope we don't have cause to regret such an attitude. Whilst I appreciate there are routes for some talented people to join "the club" that does deal with this, its not a route for everybody.
*Apologies if I have skipped some important steps in this history.