The website ThinkProgress.org has revealed details of a plot to undermine political opponents of the U.S. Chamber of Commerce. According to leaked emails, three private security firms were asked to propose a strategy for weakening progressive and labor groups that have challenged the Chamber’s lobbying for some of the nation’s biggest corporations. The groups include the labor coalition Change to Win, the Service Employees International Union, U.S. Chamber Watch, StopTheChamber.com, and Think Progress itself. One proposal called for entrapping a Chamber target by providing them with a document containing false information about the Chamber and then exposing the document as a fake once the group publicized its contents. The firms also proposed creating a “fake insider persona” to communicate with Change to Win. The three security companies — Palantir Technologies, HBGary Federal and Berico Technologies — were also implicated this week in a plot to target the online whistleblower WikiLeaks and some of its prominent supporters.