I've done it many times and never heard or saw water lines 75 riders deep. I wonder if new people are managing it and never used past experience to set it up?

Anyway it can be dangerous. I saw what I think was a rider dropped from his group. While catching up, he picked up a dozen or so riders and apparently was unaware they were behind. He passed his group who was on the side of the road and they yelled to him. He quickly hit his brakes, pulled over quickly, and pretty much everybody he pulled went into a big pile up.