The U.S. federal government's BioWatch system was launched shortly after the attacks of September 11, 2001 in an attempt to detect potential biological terrorist attacks. The system's effectiveness has been criticized by the media in the past, and a new report by the U.S. Government Accountability Office does not encourage renewed faith in the BioWatch program.

The GAO report says there is a lack of reliable information about the current system to determine if it would actually detect a biological attack. Generation-2 is a flawed system that makes it impossible for the GAO to suggest improvements, the report states.

The Washington Post reported that "DHS officials defended BioWatch program, which consists of aerosol collectors deployed in more than 30 cities nationwide that draw in air through filters.