I do empathise with Macropolo. Had a similar experience, flying back from the States with BA. A large group of French people of all ages came on board at LAX. Probably teachers and students also. They blocked the aisles, were very noisy and kept swapping their seats around. My wife and I were seated amongst them and it was most uncomfortable. During the flight they were wandering around chatting loudly to each other. The CC didn't seem to take much notice either.