The Internal Reveue Service (IRS) has temporarily suspended its online Identity Protection PIN tool in order to conduct a review of the security features of the application. The IP PIN is a six-digit number taxpayers can use as "an additional layer of protection" against identity theft. As of the end of February 2016, the IRS prevented 800 cases of tax fraud using these PIN numbers.
Suspension of the PIN retrieval application is part of the IRS's ongoing security review. For more information, click here.