In past years I remember random squealing and screaming. It comes with the age I guess....... In large groups they are sometimes a pain because they forget there are "civilians" around (ie take up the whole sidewalk, randomly stop in front of people and squeal OMG!!). But with the thousands of other guests they are mostly just fit in the general chaos.
But after a trip in January with large groups of teenage girl Brazilian tourists, the cheerleaders are nothing.