Las Vegas police have raided 112 marijuana "grow houses" this year, more than double the number raided in 2007, according to the Las Vegas Sun.

Two factors are helping the pot market. The Las Vegas economy is dismal. And there are an unprecedented number of empty homes, which are rarely checked by police or their bank owners.

Pot growers are even moving into commercial real estate, where they can rent these days without much of a background check. For example The Sun names a police raid of an industrial bakery in September that was really a industrial pot house.

This phenomenon won't get better soon, with 80% of Las Vegas homeowners underwater.

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