An "underground economy," particularly one dealing with things that would normally not be considered criminal in nature, is the response of market forces to excessive government controls. That's worth rolling around in the brain for a while.

In a completely collectivized system, like East Germany or the U.S.S.R., the underground economy was the only choice for survival for many.

Unfortunately, as happened with Prohibition in the U.S., a large, organized class of traders developed outside the laws, and hung on long after the Berlin Wall fell. There's a reason there was a large, less-than-legal group moving into control in Russia after things loosened up. They were already there.

Taxes, regulations, and things like that need to be balanced with results, and, all libertarian utopias aside, there is a working middle ground where the population will stay within the system. Go to far, and the economy dives under the surface.

Cigarette taxes are a good example. They have been raised constantly for one reason or another, far beyond reason in some states and localities, and the response has been a thriving cigarette smuggling industry. We're probably lucky that automobiles don't run on easily-portable power cells.

Sometimes regulations and government actions actually do what they're supposed to do. Regulate. Far too often, they're the equivalent of putting a penny in a fuse box.