At the moment, businesses are safe from the "irreparable harm" the ruling would cause, but the Department of Homeland Security isn't about to back down. Whereas plaintiffs like the American Civil Liberties Union and the U.S. Chamber of Commerce believe the regulation would foster workplace discrimination against legal workers who'll be victimized due to database errors, the DHS argues the ruling merely provides a guideline that would help employers avoid liability for hiring undocumented workers.
The government has been sending out "no-match" letters since 1994, but until recently, there was no penalty for failure to comply. Since employers were able to pick and choose who to fire, unions and immigrant workers alleged that businesses used the letters to retaliate against unionization and otherwise restrict workers' rights. One might conclude it's actually a fairer system is employers are required to treat each case in the same manner.
One might also conclude the regulation would herald an economic crisis for industries dependent on immigration labor.
(Immigrant Worker image by rabble)