From a UFCW press release (link):

The United Food and Commercial Workers International Union (UFCW), today, sought court intervention to protect the 4th Amendment rights of all Americans and enjoin the government from illegally arresting and detaining workers including U.S. citizens and legal residents while at their workplace.

The lawsuit - filed in the U.S. District Court for the Northern District of Texas - names the U.S. Department of Homeland Security (DHS) and the Immigration and Customs Enforcement (ICE) agency as defendants. The suit calls for an injunction against the excessive, illegal and unnecessary worksite raids conducted by ICE agents...

...Peter Schey, President of the Los Angeles-based Center for Human Rights and Constitutional Law and the lead counsel in the UFCW litigation said, "The Department of Homeland Security routinely violates the Constitution and federal law when it conducts work place raids to detect undocumented workers by engaging in mass detentions of all workers without any basis for believing that they have violated any laws. Such mass detentions have long been considered unlawful by the U.S. courts. While the Department of Homeland Security has a legitimate function to perform enforcing the nation’s immigration laws, it cannot do so by running roughshod over the well-established constitutional rights of U.S. citizens and lawful resident workers. If DHS Secretary Chertoff is unwilling or unable to stop the unconstitutional conduct of his agents, then we are sure the federal courts will step in to do so."

The suit concerns raids conducted at Swift Foods; note that Schey repurposed one of his sites into the Swift Raid Collaborative.

Perhaps one way to deal with this issue is for UFCW members to publicly ask their leaders whether they have any qualms about working with someone who has at least three links to the Mexican government and whose motives may involve something other than defending the Constitution.