It certainly doesn't sound intuitive, but an Orange County attorney plans to file a group of lawsuits designed to help businesses fight competitors who hire illegal aliens to undercut their competitor's pricing. Attorney David Klehm founded a website entitled illegalemployers.org, according to this article.
First reported widely by Kimberly Kralowec, other articles have also appeared in the Cal Law Recorder. Among others, Kim points out that one major hurdle to these actions is a 1970 case entitled Diaz v. Kay-Dix Ranch that bars just this type of action where the remedy lies with another branch of government - the legislative branch, where the job falls to control immigration or not. The Courts call it the "economic abstention doctrine," and it means they won't interfere when it's not their place to do so.
MIPTC is not aware of any suits filed by Mr. Klehm yet, but will report on them when they become available, and the court's decisions.