A new law penalizing employers who hire illegal immigrants took effect at midnight on Tuesday.

But thousands of Arizona employers have yet to use the free government service to determine if their workers are legal.

"It's a touchy situation," said Zip Killeen, owner of the Tee Pee Mexican Restaurant in Central Phoenix. 

"But the people voted for it, we have to abide by the law."

The law punishes employers who knowingly hire illegal immigrants. 

Because of that, Killeen registered his business for e-Verify, a service run by the Department of Homeland Security which checks a worker's documentation.

Not many of Killeen's colleagues have joined him.

Only 7 percent of all employers in Arizona have registered for e-Verify.

"Wasn't part of their new year's resolutions I guess to get signed up for e-Verify," said Jay Zweig, a Phoenix employment lawyer. "There has been a lot of publicity and e-Verify is free and easy. I think people have just been sitting on the sidelines looking at the legal challenges and they're still not sure what's happening."

Killeen doesn't have the answers but he hopes whatever fallout may come doesn't impact his bottom line.

"Nobody knows what's going to happen until it does so let's cross our fingers and hope it doesn't affect us," said Killeen.

Employment lawyers say e-Verify gives you one of the strongest defenses you can have if ever accused of hiring illegal workers.