As Gutto said, the major problem of BIG is that they're mostly teenagers-only groups on the loose (many of them away from their parents for the very first time) with one or at best two tour guides to "handle" all of them. So this "freedoom" they get for one or two weeks leads them to behave like that.
About the cutting lines, sadly this is a terrible "policy" supported by the
travel agent guide. Due to the slow mobility of a large group and the guidelines those guides have to cover almost every major attraction in a day they rush from an attraction to another with part of the group while other members of the group still in the bathroom/shops. This happens because they guides usually says for those who get behind that they will be able to "join the group when they get to the attraction", so you see the horde of teenagers cutting the lines... I think thei is awful, unexcusable and really bothers me...
Is there a more specific time of year when they travel?
crzy4dsny, July is the peak for BTGs, we can't precise you when in July because although July is winter break here in schools, every school give them a 2 week break, but those weeks can de diferent from a school to other. mostly you can expect more BTG on the second, third and fourth weeks of July, as in the first week almost every school still in class. This years (from what I read on the local paper ads) the peak was the third and fourth weeks for groups from Rio de Janeiro.
You'll also find them between January/February (fewer groups than in July)
About resorts, due to Disney rates, the majority of BTG stays out of the world (usually somewhere around International Drive or US 192) because they also do US, IOA and/or SW. For those groups that do stay in the world almost all groups go to the Value resorts. You'll rarely see them in other resorts. And when staing in All-Star they don't loose time visiting other resorts.
EJ Gracie, I don't know about those policies towards BTGs, but when I visited Disney for the last time (Feb 2002), and stayed with my wife in BC resort (not with a BTG

) we had a most pleasent visit and were treated like a regular guest regardless of where we were from. But I do beleive that they take those policies towards BTGs, because I've seen many weird stuff going on those groups.
And to finish this long post (sorry

), I'd like to say that BTGs bother me a lot too, and what I do when I cross with them in a park, is try to avoid them making their presence less noticed. That is the same thing that I do when I cross with those cheerleader competition groups.
This behavior as told before is unexcusable, but you can't take this as the regular behavior of all brazilian visitors, becuase there are many other brazilian visitors (families and couples) to prove otherwise
