So the original thread got sidetracked by a few individuals arguing about their point of view. In spite of that, I think we can agree on the following:
Group rides bring out behaviour you wouldn't see with 2 or 3 guys who know and trust each other.
People tend to ride over their heads in group rides when they feel the need to keep up.
Group rides tend to attract newer riders - a higher risk group.
Passing, following too close, reckless speeding are characteristics of many group rides.
Experienced riders do not participate in group rides, except with a very small group of trusted friends.
People are attacted to group rides for the sense of "belonging" to a social group.
So, what have we learned? For you newbies, group rides can spell disaster. Do not participate unless you have total confidence in your ability to practice sound judgement. For experienced riders - set an example when you're around others. Have that pre-ride talk. Pull aside those who exhibit unsafe riding techniques. Walk the talk.
If anybody has been reading all this stuff, I hope they come away with one message: When you twist that throttle wide open - be sure. Make good decisions. Keep a cool head - ride YOUR ride - don't get sucked into being a follower.
If any of this shit makes one person use their head a little more, then it's all worthwhile. It's all about using good judgement.