We extensively covered the two Wisconsin "John Doe" cases in which prosecutors targeted Scott Walker and conservatives in Wisconsin.
John Doe No. 1 concerned Walker's time as Milwaukee County Executive.
John Doe No.2 was the more notorious, as a Democratic lead prosecutor unleashed the equivalent of SWAT teams on conservatives, raiding homes, seizing electronic records, and generally terrorizing innocent people.
It was a nasty, vicious investigation (note: Michael Lutz in this interview from late April 2015 committed suicide
in late July 2015).
John Doe No. 2 was definitively shut down
by the Wisconsin Supreme Court, which found that it was based on a faulty and unconstitutional legal theory, and employed outrageous tactics that never should be repeated (emphasis added):