They're banned on the order of thousands upon thousands every single week.
The problem arises from two factors: 1) it is trivial to make a new account and 2) the process is likely automated and making use of disposable email services.
I don't know why people are so strung up on violet cubes. Sure, they give you six lines to pick three of, but they have just as much chance of being complete garbage as they do with a red or black cube. One good line and five garbage lines? You have to pick three. Next cube? Six different lines again, four of which are utter trash. And you must pick three. Next cube! Six lines to choose from, three of them are really good, but horrible for the weapon type(say, m.att% on a w.att weapon). Choose three. Next cube! All six lines are crap. You see where this is going?
To put it short, violet cubes are just as likely to give you trash lines as red, black and even meister cubes. And that seems to be the part everyone misses.
Also, making petitions doesn't really get anything done unless it's a local matter. Online petitions are an utter joke, as they can be influenced by people who are far outside the scope of what the petition encompasses. The only thing petitions are ever successfully used for is, for example, bringing something to the attention of your local city council. If a petition goes beyond the scope of a single town or community, then it's completely worthless.
