There are multiple theories (and philosophical underpinnings) on the purpose of punishment. The one you've identified is deterrence: We should punish so that pe

There are multiple theories (and philosophical underpinnings) on the purpose of punishment. The one you've identified is deterrence: We should punish so that people don't do the bad thing in the future. But another one is retribution: By causing harm, you should have some harm done back to you. To even the scales of justice as it were. Your argument is a very solid one for why a sanction is not needed for deterrence. The court of public opinion has punished him enough. But what about when the next attorney does this, or the 100th, and it's not novel enough to get a bunch of NYTimes coverage? If they get sanctioned, will they not say "What about the first guy? He didn't get sanctioned?!" Will there be some doubt that justice was really done? Think about the cases where some rich white kid skates by with a slap on the wrist for some widely-publicized crime and the judge says, in effect "Look, this is a good kid from a good family who's been widely castigated in the press. He's getting kicked out of his Ivy league school and probably won't even get hired at a top law or consulting firm in the future. Is it really necessary to send him to jail like a poor person? Hasn't he suffered enough?" I'm not saying it's the best or only argument, but there is an argument for the court imposing sanctions purely on conduct with the court, and ignoring what the newspapers are doing.