无恶不作為
[wú è bù zuò wèi]
'No action is left behind that isn't vicious', which means this person does bad things boldly. This seems negative but it may not mean true immorality - people might just want to present their uniqueness or rebellious nature through exaggerated expressions. Alternatively they could take it as an attitude to defy the conventions courageously when necessary, regardless of the criticisms.