For those who are not already aware (ICE) Immigration & Customs Enforcement, have a toll free phone number. My guess is that hundreds of 'Whistle-Blowers' are using this opportunity to communicate intelligence of suspicious goings-on in businesses. I suspect that a citizen who saw the safety violation issues and the hundreds of non-English speaking people working at Postville, Iowa used this method.

Either he/she informed the local police, who then contacted ICE and then used this informant to produce largest raid in illegal immigration history. It makes sense that once the general public have seen the success of the cooperation of local police and ice agents, other American patriots, will become a 'Whistle Blowers"
Hopefully if the SAVE ACT becomes law, giving extra funding to Ice and other enforcement. People outside the law will think it prudent, to leave and not live in abject fear of being detained.