During Pedalpalooza in Portland, I saw a crowd of bicycles about 10 blocks long and 5 bikes wide.
No doubt a few hit some stale yellow lights, and more than one bike made it through a stop sign at a time.
If they all took the lane, and had gone one at a time though the stop signs, it could have taken hours to get everyone down the road. Perhaps they would have been better off spreading out to a crowd moving 10 blocks wide
Sometimes it is best for the crowd to just go and try to open the streets up to traffic as quickly as possible.
The classic bike ride I was on, we only had about 10 to 20 riders... not too big of a group, but trying to allow cars to pass and inserting cars into the middle of the group didn't work well.
Fortunately most of the Portland drivers seemed to have a fair amount of patience.
As far as rolling stops, I suppose most tickets are given when there is no traffic, because at least the attentive cyclists will stop for cross traffic. So the tickets become an annoyance for the safety conscious riders who DO STOP when necessary.