On June 9, 2008, Customs and Border Protection (CBP) issued an interim final rule which implemented the Electronic System for Travel Authorization (ESTA) for aliens who travel to the United States under the Visa Waiver Program (VWP) at air or sea ports of entry. Under the rule, VWP travelers must provide certain biographical information to CBP electronically before departing for the United States. This advance information allows CBP to determine before their departure whether these travelers are eligible to travel to the United States under the VWP and whether such travel poses a security risk. The interim final rule also fulfilled the requirements of section 711 of the Implementing recommendations of the 9/11 Commission Act of 2007 (9/11 Act). In addition to fulfilling a statutory mandate, the rule served the two goals of promoting border security and legitimate travel to the United States. By modernizing the VWP, the ESTA increases national security and provides for greater efficiencies in the screening of international travelers by allowing for vetting of subjects of potential interest well before boarding, thereby reducing traveler delays at the ports of entry.