Hundreds of employees of the restaurant chain owned by Chipotle Mexican Grill Inc. were fired after immigration authorities conducted a "digital" raid. The news has sparked alarm throughout the immigrant community. 

"Digital" or "silent" raids began to occur more frequently in mid-2009 and comprise part of the Obama administration's immigration policy. Since then, the administration has carried out more than 3,000 inspections, investigated thousands of workers, and issued fines totaling more than $7 million. 

Walmart and McDonalds are among the most well known restaurant chains where digital raids have been carried out, but any company can be checked, no matter how small. 

In contrast to traditional raids, where hundreds of federal agents arrived at one location and arrested employees who were unable to show documents authorizing them to live and work in the United States legally, a special Immigration and Customs Enforcement (ICE) unit now reviews the identification data for millions of workers and compares the information to a huge database operated by the Department of Homeland Security (DHS). 

If any of the employee's data does not match up with the government's findings, the employer receives a letter from DHS that informs them of the problem. If the employee doesn't produce the missing documents, he or she gets fired and the boss gets fined. 

Richard Stana, of the Congressional Budget Office, which prepares reports for legislators, said that between October 2009 and August 2010, approximately 14.9 million background checks were made on individuals working for nearly 222,000 employers. 

Of these background checks, 97.4 percent consisted of people who had permits to work legally; 2.3 percent resulted in finding undocumented workers. The other 0.3 percent was related to job seekers whose legal status was questionable, but it was confirmed later on that they had papers, according to Stana.

Theresa Bertucci, the associate director of enterprise services at U.S. Citizenship and Immigration Services (USCIS), said that the number of background checks has risen from 3.27 million in the 2007 fiscal year to 16.4 million in the 2010 fiscal year, and that more than 246,000 employers are currently participating at more than 850,000 locations.  

Bertucci described progress and improvements in the system that compare the job seeker's data with more than 455 million Social Security records, more than 122 million passport records, and more than 80 million immigration records.