You should do this whenever you get a chance... There is a new credit agency that is selling this info to telemarketers..
wnbc.com - Money - Credit Agency Giving Consumers Something Else To Worry About
Removal of Name from Credit Bureau mailing lists - to remove your name from mailing lists that are prepared by the credit bureaus, call 1 (888) 567-8688 or 1 (888) 5 OPT OUT. You can remove your name from the mailing list for a period of 2 years over the phone. To remove your name permanently from the mailing lists, request a form over the phone to be mailed to you, fill out the form, and return the form. Calling this one phone number will remove your name from the mailing lists prepared by the 3 credit bureaus of Equifax, Transunion, and Experian.