O'Keefe said MTV's "Punk'd" set such a precedent, though it obtained releases prior to airing footage of well-known celebrity figures.
The judge also struck down back-stabber Hannah Giles' claim she was not liable because O'Keefe held the hidden camera.
The civil case brought by fired ACORN employee Juan Carlos Vera moves now forward.
O'Keefe is represented pro bono by attorneys hired by CIR, a legal institute co-directed by Larry Arnn of Hillsdale College. Not ironically, his lawyers charge more than the $75K Vera is suing for.
This is the 3rd case brought for the ACORN sting videos and his fourth federal case. O'Keefe has settled out of court once and taken a plea deal once.