A superhero, Superguy, is active and working in the present day. Saving lives, defeating criminals, saving the Earth from giant meteors, and so on. Doing all the things that are impossible for law enforcement, or at the very least prohibitively expensive. There are no other superheroes.
However - he has an unpleasant flaw. He himself has admitted to having this flaw, and chooses to not seek treatment/submit to punishment for it willingly. Apart from this flaw, he continues to do heroic work otherwise.
Let’s say the government has the ability to force him to undergo punishment/treatment for this flaw; they have a kryptonite cage. Obviously, though, while he’s in the cage, he can’t go out and save people or stop crime. Plus, he’s likely to carry a grudge, and so may not be so willing to help out in the future.
How much illegal behaviour are you willing to accept before the government should incarcerate Superguy? Should they step in if he’s a petty thief? A bank robber? A pedophile? If Superguy kills one person for every two he saves, should he be locked up?