After reading this entire thread, I am a little apprehensive about my groups dive trip to Sipadin/Mabul this May. I am not sure I will be able to hold my tongue if I see someone, of any nationality, "riding a turtle". It will be difficult for me not to quietly, turn off someones' air, if I see them plucking feather pens and passing them around for "entertainment". I might even go so far as to spiking someone's drink at the resort with ex-lax if I see them laying on coral. I am a DM that was raised to respect and protect the ocean environment. How did you all stand by and not go mad with anger at the attrocities you saw. I am sure you did your damndest to report it but DANG! I bet you wished you could have inflicted some near fatal attack of the runs or something! I hope and pray my group doesn't see this kind of behavior because I am not sure what I would do. And your right, they could be black, white, japanese , korean, scandanavian, male or female and I would feel exactly the same way towards them. I guess the best way to stop this crappy diving technique is to educate and lead by example. But the ex-lax idea sounds a lot more vindictve and effective(for the short time).
Here's to better divers...in every country.