For the youngsters here, the Max Headroom TV hijacking was, I believe, the greatest hack of my lifetime. I hope it’s never solved. https://en.m.wikipedia.org/wiki/Max_Headroom_signal_hijacking

@mattblaze I fI remember correctly the closest they came was determining the area it came from. Considering the WGN and WTTW studios were in the same general direction from the Sears tower and near enough to each other, the North to near Northwest side was where the signal came from.
As far as who, not even the Chicago underground BBS world had anyone bragging about it. Any admission at this point would be unverifiable.