Following the September 11 terrorist attacks, the US Government took a number of steps to tighten rules governing international financial transactions, philanthropic grantmaking, and other resource flows from US-based charitable institutions. These included Executive Order 13224 (September 2001), the Patriot Act (October 2001), and the Anti-Terrorist Financing Guidelines: Voluntary Best Practices for US-based Charities, issued by the Treasury Department in November 2002.