(Fox News) Dozens of conservative groups that support Wisconsin Republican Gov. Scott Walker reportedly have been subpoenaed by a special prosecutor demanding donor lists and other documents pertaining to their backing of Walker's union overhaul and recall fight.
The so-called "John Doe" investigation bars those subpoenaed from talking publicly.
But Eric O'Keefe, director of the Wisconsin Club for Growth, told The Wall Street Journal recently that investigators have raided at least three homes and that he "wants the public to know what is going on," despite the personal risk.
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He also suggested the probe is having a chilling effect on conservative groups as Walker approaches a 2014 re-election effort.