A federal law crafted to fight the mob is giving marijuana opponents a new strategy in their battle to stop the expanding industry: racketeering lawsuits.

A Colorado pot shop recently closed after a Washington-based group opposed to legal marijuana sued not just the pot shop but a laundry list of firms doing business with it — from its landlord and accountant to the Iowa bonding company guaranteeing its tax payments. One by one, many of the defendants agreed to stop doing business with Medical Marijuana of the Rockies, until the mountain shop closed its doors and had to sell off its pot at fire-sale prices.

With another lawsuit pending in southern Colorado, the cases represent a new approach to fighting marijuana. If the federal government won't stop its expansion, pot opponents say, federal racketeering lawsuits could. Marijuana may be legal under state law, but federal drug law still considers any marijuana business organized crime.

"It is still illegal to cultivate, sell or possess marijuana under federal law," said Brian Barnes, lawyer for Safe Streets Alliance, a Washington-based anti-crime group that brought the lawsuits on behalf of neighbors of the two Colorado pot businesses.