Now HERE is a sport that I can get into.
A description of what they are, in their own words:
The CTFL was created out of a desperate need to better train and arm citizens with cardboard tubes. While many speculate that our fore fathers, when drafting the constitution, originally intended the fourth amendment to refer to firearms, there is now a small group of non-academics who believe that they were more likely referring to elite militias of card board tube wielding ninjas.
Check out the website, fun stuff with fun photos. Hilarious.