United States Government Publishing Office publisher pbl distributor dst United States Government Accountability Office author aut Government Organization text government publication eng GAOREPORTS Legislative Agency Publications gao legislative 2010-08-12 U.S. Government Printing Office 2003-10-16 monographic deposited born digital 25 p. GA 1.13:GAO-04-170T https://www.govinfo.gov/app/details/GAOREPORTS-GAO-04-170T P0b002ee180374342 f:d04170t DGPO 2010-08-12 2011-03-28 GAOREPORTS-GAO-04-170T machine generated eng fdlp REPORT GAOREPORTS-GAO-04-170T GAO-04-170T Illegal aliens Immigrants Counterterrorism National preparedness Immigration information systems Systems design Systems evaluation Homeland security Canada Mexico DHS Visitor and Immigrant Status Indicator Technology Program Testimony A08732 Each year, millions of visitors, foreign students, and immigrants come to the United States. Visitors may enter on a legal temporary basis--that is, with an authorized period of admission that expires on a specific date--either (1) with temporary visas (generally for tourism,business,or work) or, in some cases (2) as tourists or business visitors who are allowed to enter without visas. (The latter group includes Canadians and qualified visitors from 27 countries who enter under the visa waiver program.) The majority of visitors who are tracked depart on time, but others overstay. Four of the 9/11 hijackers who entered the United States with legal visas overstayed their authorized periods of admission. This has heightened attention to issues such as (1) the extent of overstaying, (2) weaknesses in our current overstay tracking system, and (3) how the tracking system weaknesses and the level of overstaying might affect domestic security. https://www.govinfo.gov/content/pkg/GAOREPORTS-GAO-04-170T/html/GAOREPORTS-GAO-04-170T.htm https://www.govinfo.gov/content/pkg/GAOREPORTS-GAO-04-170T/pdf/GAOREPORTS-GAO-04-170T.pdf GAO-04-170T https://www.govinfo.gov/app/details/GAOREPORTS-GAO-04-170T Testimony GAO-04-170T; Homeland Security: Overstay Tracking Is a Key Component of a Layered Defense; Illegal aliens Immigrants Counterterrorism National preparedness Immigration information systems Systems design Systems evaluation Homeland security Canada Mexico DHS Visitor and Immigrant Status Indicator Technology Program