A few fan experiences for me, both at Kinnick and on the road.
At Wisconsin:
The first time I went there I was with my wife (GF at the time, no pics) and every time we clapped, cheered, or anything for a good Iowa play, the people around us told us to sit down and shut up. One guy shoved me. I was not trash talking, just clapping and high fiving my GF after an iowa score. There were threats of increased violence, but none came.
A few years later, after the game, we had lost, I was walking with my friends back to the car. I was lagging about 10 yards behind the group, quietly rehashing the game when a guy ran across the street, grabbed my lapel, pulled me up to his face and screamed "I'm gonna kick your effing ass.". Fortunately my friends heard it, turned back and the dude scrambled when he realized it wasn't just him and me (he was well over 6', I'm about 5'7").
At Minny:
"Who hates Iowa" the instant my foot crossed the threshold of "The Library", a bar there. People kept taking my Iowa hat and throwing it on the dance floor..stupid crap like that. I basically ignored it. One of the people I was with got in a fight, but knowing him, he probably earned it. At the game, we were abused verbally the whole game, but I have to admit, we were sitting in the minny student section (a dipwad co-worker/minny alum didn't tell us the tickets were in the student section when he said he could get tickets for our group).
jNW
We had fun there. Iowa owned pretty much every lot. At the game, I was harassed by the jNW fans, but nothing bad.
Illinois
This was last year...we had a blast and Ilinois fans were pretty non-descript.
Kinnick
We had a large group of Wisconsin fans in the south endzone that were literally trying to get a fight started. The were complete arseholes.
I sat in the visitor section for a PSU game (2010). The PSU fans were great....plenty of good natured ribbing both ways, but we all had a good time.
Dental lot in '09...drunk Iowa fans throws a beer at a Michigan fan as he was walking by their tailgate. Other Iowa fans grabbed him and gave him a pounding. MIchigan fan was grateful for the support.