Fraud with housing tax credit for first time house buyers

I wonder what percentage of frauds are even investigated by the government.

The new sales data could help backers of the credit, scheduled to expire Nov. 30. But the improvement also could undercut a key argument of backers -- that the recovery remains fragile enough to require an extension. It also doesn't alleviate concerns the credit has been subject to widespread abuse, as the Internal Revenue Service pursues more than 100,000 suspected improper claims. . . .