If you own a home in Los Angeles, watch out for the scammers. Your city leads the nation in mortgage fraud, according to the FBI's annual mortgage fraud review.

The FBI's Los Angeles field office took 9,971 reports of suspicious mortgage activity in 2008. That's far ahead of the second-place city in the United States, Miami, which logged 5,155 suspicious activity reports.

According to the FBI, some of the more common mortgage fraud schemes include builders offering secret incentives to home buyers. For instance, builders will falsely inflate a purchase price to make it look like buyers have made down payments when they really haven't. In these cases, if the homes fall into foreclosure, lenders are unable to recover any home equity.

Another popular scheme involves groups using straw buyers to default purposely on a mortgage loan. The group then buys the property at a deep discount from a mortgage lender through a short sale. Perhaps the most painful fraud are the foreclosure rescue scams. In these cases, criminals pretend that they are helping borrowers who are facing foreclosure. Instead, though, they secretly take over the property's deed.

All of these are scummy crimes, and this kind of activity leaves behind a lot of bewildered victims. These victims suddenly face serious money problems.

Unfortunately, there are always going to be scammers out there. The best defense is to be on guard at all times. If someone calls you out of the blue offering to help you reduce your mortgage payments, hang up the phone. It's surely a scam artist of some sort. And even if the caller isn't doing anything illegal, you can bet that he or she won't really be able to help you reduce your mortgage payments.

If you need to reduce your monthly mortgage payments, call your mortgage lender directly. That's the safest, and surest, way to go.