Erm, what's up, Growtopians.!

I made this thread just to know whether buying/selling Growtopia Accounts for World Locks is legal/not.
Well, if it is need for me to give some informations, me myself kinda well-known in certain Growtopia Community, and being asked to help them doing transactions related to buying/selling Growtopia Accounts (as a middleman in short), and I want to know, is it actually legal to do so? (since all this time, I always thought that the things that I've done so far is just helping others to do the transactions).

Once I also asked this questions, and I got so many different answers, that makes it unclear for me personally.
That is also why I decided to post this question on Growtopia Forum to get the certain answer xD.