This times 100. You don't even have legacy names in other games. In fact, the people complaining about this and security should be praising this game's sytem for the exact opposite of what you are trying to say. You get ONE free legacy change. After that, you have to have a new account/new characters on a new server and level high enough on one of them to unlock legacy in the first place.
So you are telling me that we should be freaking out that people are going to use this ONE time service to start a Fraud ring in order to loot every Gbank on their server? With their army of 100 criminal cohorts along with them? Give me a break.
It's easier to pretend to be someone else in just about every other game. Guild Wars 2 is the only one currently where it is not possible at all, since you show up as your account name no matter what toon you are on.