.... The IRS said in late May the tax return information of about 114,000 U.S. taxpayers had been illegally accessed by cyber criminals over the preceding four months, with another 111,000 unsuccessful attempts made.

A new review has identified 220,000 additional incidents where data was breached, the tax collection agency said. It identified another 170,000 suspected failed attempts by third parties to gain access to taxpayer data.

The attackers sought to gain access to personal tax information through the agency's "Get Transcript" online application, which allowed taxpayers [and cybercriminals] to call up information from previous returns....