I'm nervous when groups that large pass me on closed roads. Most of the riders in big groups that have passed me on rides have not been very considerate, honestly. I was on Tour for Woodside on a closed road and a huge group of riders knocked another cyclist who was going up hill more slowly then they were, into the bushes. I stopped to help, they kept racing. I'm not saying that this group is like that, but I have seen the absolute disdain that some elite cyclists have for anyone who is not of their caliber, that I could see how such a group could be considered a threat to public safety.