Yesterday I attended a House subcommittee hearing on "e-verify," a now-voluntary federal system that verifies the legal status of people working for a very small number of U.S. employers. Heath Shuler (D-N.C.) has introduced a bill that would make the system a regulatory requirement for every employer in the United States, over objections from people who say a national rollout of a program built on faulty databases will be a bureaucratic nightmare. There is also the question of whether citizens should have to ask the Department of Homeland Security for permission to work.

Also in attendance was Traci Hong, a naturalized American citizen who apparently had to visit the Social Security Administration six times before she was permitted to work. Hong also happens to be an immigration lawyer working for Rep. Zoe Lofgren (D-Calif.), who chairs the House subcommittee on immigration and citizenship. There are very few people on Earth who can navigate the immigration bureaucracy as well as Hong, but it took her a week to clear her status with the SSA. Hong was in D.C. and could demand some kind of attention; imagine the same situation for a legal Spanish-speaking worker in rural Arizona.

Throughout the hearing, Shuler relied on various degrees of innumeracy while accusing employers of "exploitin' immigrant labor" and forcing people to endure "inhumane desert conditions." The social security database e-verify uses has a 4 percent error rate, though Shuler claims the overall system has an error rate of half a percent. Both of those numbers sound insignificant. Iowa Republican Steve King says "The accuracy of the e-verify system is remarkable!" and "almost perfect!" But 4 percent of 153 million workers is 6,120,000. (Half a percent is 765,000.) That's a lot of people who will have to wrangle with the federal government before showing up at the office.

There is reason to doubt the half a percent claim, which relies on some highly dubious conjectures on the part of the DHS. Currently, 5.8 percent of e-verify submissions come back as a mismatch, and employees can contest if they like. Half a percent fight back and eventually get permission to work, as Traci did. 5.3 percent "walk away from the process." "They're illegals!" exclaims DHS. That's certainly one explanation, and some number of them surely are undocumented. But last week in Phoenix, I was hearing stories of legal Latino workers who were fired as soon as e-verify registered an initial problem. One study has found that a third of employers who use e-verify illegally "pre-screen" employees, meaning that they simply won't hire anyone who isn't immediately approved. Not everyone walking away is undocumented. They're just workers with suspicious last names who happen not to be high-powered immigration lawyers working on the Hill.

Even if none of this worries you, shouldn't we be at least a little bit alarmed by something called "e-verify" in 2008? It sounds like something Prodigy would have rolled out when I was nine.