Lien, Mean Publicly Available Tax Data

Between 2002 and 2005, the IRS sent out more than 2 million tax liens containing the full Social Security numbers of recipients, New York Times reports today. The Government Accountability Office says many of those documents are still publicly available to identity thieves.

Last year, the tax agency started truncating Social Security numbers to the last four digits in its notices. But that's not foolproof either, because many large data vendors sell millions of government records with the first five digits of Social Security numbers, which criminals could combine with the tax lien data to reconstruct full numbers.