A letter report issued by the Government Accountability Office with an abstract that begins "The Internal Revenue Service (IRS) has a demanding responsibility in collecting taxes, processing tax returns, and enforcing the nation's tax laws. It relies extensively on computerized systems to support its financial and mission-related operations. Effective information security controls are essential for ensuring that information is adequately protected from inadvertent or deliberate misuse, disruption, or destruction. As part of its audit of IRS's fiscal year 2005 financial statements, GAO assessed (1) the status of IRS's actions to correct or mitigate previously reported information security weaknesses at two sites and (2) whether controls over key financial and tax processing systems located at the facilities are effective in ensuring the confidentiality, integrity, and availability of financial and sensitive taxpayer data."