I'm not here to discourage bad behavior. However if I see, it I'm not going to leave it be. I'll at the very least speak up about it and/or call the individual out.

Encouraging the good is definitely the better way, but that doesn't make negative feedback any less necessary. Everyone does bad things from time to time, despite all the encouragement in the world to do good. Although their number is tiny, we can't ignore those who do evil because its pleasurable to them.

We have a responsibility to keep each other accountable in proportional ways. Even the Lightning network has watchtowers and penalty transactions for when people try to cheat. Proportionality is the key here. We should strive for the golden mean. Your email example is perfect. People have definitely done evil with email. That doesn't mean we install a mass surveillance state. That would be a gross overreaction.