--this means that when someone applies for credit using your SS# and other info, the lender is obligated to call you to confirm that it is really you who is applying. If you are currently applying for a mortgage or car loan, this can slow down the process in that you must be available to answer a call verifying that it is you. It also means you can't sign up for "instant credit approval" in a store (of course you can apply, but you can't be approved "instantly" unless you put your cell phone number on the form and are called in the store where you're applying). This, in fact, is exactly what "LifeLock" does--it places fraud alerts with the 3 credit bureaus, a service that you can do easily for free. It lasts for 90 days and then must be renewed. When you notify one credit bureau to place a fraud alert on your report, that bureau is obligated to tell the other two to do the same thing.
There is more info here:
http://www.fightidentitytheft.com/flag.htmlSome of what they say is a bit contrary to what I say, namely that the other 2 bureaus will definitely also do the fraud alert (but they are supposed to).
I have done this several times, and always heard within just a few days from all three bureaus that I could now get a copy of my credit report from them by filling out a quick form to request it.
Each of the bureaus has a page on its website dealing with fraud alerts:
equifax:
https://www.alerts.equifax.com/AutoFraud_Online/jsp/fraudAlert.jspexperian:
https://www.experian.com/consumer/cac/InvalidateSession.do?code=SECURITYALERTtransunion:
http://www.transunion.com/corporate/personal/fraudIdentityTheft/preventing/fraudAlert.pageA "credit freeze," on the other hand, is much stricter and can make getting credit quite tricky. I was told by someone at one of the bureaus it could make it virtually impossible.