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You guys should know that even if trading a bitcointalk account is forbidden, lots of people will still do it underground, people tend to violates the rules
Saying that people will do it underground makes no sense as a wrong thing is wrong. Making it legal out here does not make it right in anyway. People who want to scam or do illegal things will do it no matter what's the outcome but by imposing a law/rule may make things better.
We have a legal system in every country but still people commit a crime knowing that they will be punished. So does it mean that there should be no legal system in any country?