I also disagree with your characterization of the lasso as mind control. As others have said, the lasso's powers have changed quite a lot over time. I'm not sure what it does now. If we are talking about the generic truth aspect of the lasso, it is not mind control. She does not see into their mind or perceive their thoughts. The lasso merely prevents any one from telling a lie. It is constraining an individual in the sense that it denies that person the ability to lie. It is a form of restraint. It would be the same as if she tied someone up in the lasso, rendering them unable to move. They no longer have the option to run away. I don't think there is any greater moral obligation for the former than the latter.
Now if you want to talk about some of the other more exotic powers of the lasso, then you might have an argument. I would counter that by saying how rarely you ever see Diana exploit any of them. She knows what a powerful abilities it wields and she is hesitant to use them.