Not to hack the forum here but what do you mean by freezing your credit? I mean if I am worried about something I will do that but is there something else your talking about?
Check out the links I posted above for a lot more information, but freezing your credit will actually prevent third parties from taking out unauthorized credit in your name. When a nefarious person tries to take out a loan or a credit card in your name with information they can easily find or buy for next to nothing online, the issuing party will attempt to run your credit report. With credit "frozen", this will stop the process and the credit will be denied. This will have no impact on your existing credit cards or lines of credit. If you want to open up a new card, you'll have a code that you use to temporarily lift your credit freeze in order to get the credit check to go through.
As an FYI, this can't prevent theft of *existing* credit card numbers, although nothing really can, so you'll still want to check your monthly credit card statements.
As my links up above discuss, however, credit monitoring itself is retroactive and basically worthless. Hook up CreditKarma (for free, if you want) before you do a credit freeze and you'll still be able to use that service once the freeze is in place.
