If you've ever seen or heard a LifeLock ad, you know that CEO Todd Davis proudly announces his Social Security number – essentially challenging thieves to steal his identity.

Clark is often asked about whether or not Davis' company offers a legitimate service. First off, yes, LifeLock is a legitimate company. However, Clark doesn't believe they're very effective at protecting your identity. Now the CEO is being sued in Maryland, New Jersey and West Virginia by customers who say his service doesn't work.

LifeLock's business model is based on repeatedly putting fraud alerts on your credit files. These alerts are meant to raise a flag to potential creditors so they carefully verify an applicant's identity. Too often, however, the alerts are ignored and credit is extended anyway to thieves using your name.

The truth is there's no perfect way to prevent ID theft. In the event of a theft, the banks and credit-card companies know it's cheaper to deal with write-offs after the fact than to institute industry-wide practices to end the threat before it begins.

So what's the best available solution? Do a credit freeze. This will shut a criminal down cold when it comes to applying for credit in your name. They can still take a card from your wallet and charge it up, though. But that's the least harmful crime in this arena.

Credit freezes are not a panacea and can be somewhat of hassle to establish. That's why Clark has compiled his credit freeze guide to help you through the process. When you do want to use credit again, "thawing" your records can take from a few minutes to a few days, depending on your state of residence.