Just saw Dateline will be having a segment on how contractors are scamming people and how to protect yourself when you hire one. It is being reported by Victoria Corderi. Check your tv listing.
From what I saw it looks to bring the severity of this problem to light.

 Investigating home contractors
"Dateline's" Victoria Corderi reports on unscrupulous home contractors and the families who say they have broken their dreams and wallets.