The Kutztown University student mentioned here was actually denied a warning prior to his arrest, which occurred less than three minutes after he put up his sign. Believe it or not, this sign read "Equal Rights for Robots" and was intended as a means to lighten up the crowd as things were starting to get rather heated between the protesters and the students at KU.
It's unbelievable that something the likes of this could possibly occur, especially considering that the student's efforts were in good spirits and he wasn't actually disturbing anyone.
Hopefully he shall be forgiven by the magistrate for this 'slight'. If he isn't, I will certainly have lost a bit of faith in humanity.