Not sure which is better.
As a trivial example: In 2005, when Facebook was a non-trivial company, Zuckerberg [0] guest lectured at a Harvard CS50 class. When asked if Facebook would contribute to open-source, he said that he didn't foresee it being worth the trouble (can't find the exact timestamp, so this is all IIRC with a grain of salt). Now of course, open-source is a substantial part of Facebook. Is it because Zuckerberg in the following years had a Road to Damascus experience with Richard Stallman? Maybe, but it's more likely that Facebook evolved into the type of organization where OSS became a benefit to the bottom line, and it was a decision made by people lower than Zuckerberg at that point.
Even if Zuckerberg is still as much a creep as he was in private IM messages as a 19-year-old, he's no longer the sole captain of his tiny boat. Him breaking the law means that many people end up getting in legal trouble, i.e. it doesn't really much matter what he alone thinks is moral when he has dozens of people/potential whistleblowers looking over his shoulder with greater moral concerns.
Edit: What's above isn't quite right. There was a witchhunt, but unrelated to the leak of those old IM messages. Apologies. My point below, though, stands.
A mea culpa about the messages, and how you've changed personally in the meantime would have been a change.
And looking for (and finding) a specific person who has violated a specific, well-understood rule and sanctioning them is not exactly what a witch hunt is.
The value of mea culpas is under-appreciated. We all make mistakes, and you can't change that in life. But you can change course after recognizing a mistake has been made.
I personally find that the worst people I have interacted with in life are also those who cannot assert a mea culpa.
Edit: Ugh. The witchhunt above was unrelated to those IM messages. Apologies for the mis-step.