The immigration reform measure the Senate began debating yesterday would create a national biometric database of virtually every adult in the U.S., in what privacy groups fear could be the first step to a ubiquitous national identification system.

Buried in the more than 800 pages of the bipartisan legislation (.pdf) is language mandating the creation of the innocuously-named “photo tool,” a massive federal database administered by the Department of Homeland Security and containing names, ages, Social Security numbers and photographs of everyone in the country with a driver’s license or other state-issued photo ID.