That's not a good enough excuse. I'm frustrated that you trivialize intentions to hand over people's e-mails, addresses, pictures like it's nothing, "oh, but he was just 19!". I was 19 once too, did a lot of stupid stuff, but even then I was never willing to hand over pictures/private details about thousands of people to my friends (I could have -- I was the owner of a fairly popular forum when I was 16 which had roughly 10k users).

What irks me about the quote is how specific and self-assured he sounds:

    Zuck: Yeah so if you ever need info about anyone at Harvard
    Zuck: Just ask.
    Zuck: I have over 4,000 emails, pictures, addresses, SNS
    [Redacted Friend's Name]: What? How'd you manage that one?
    Zuck: People just submitted it.
    Zuck: I don't know why.
    Zuck: They "trust me"
    Zuck: Dumb fucks.

It is very difficult to buy that he's since then done a complete 180 degree turn. He is of course aware that he can't hand his friends private information of FB users because there'll be consequences (like FB going down, his wealth going down, his reputation going down), but what the chat message tells us is what Mark is really like, what his conscience is truly like: if he's willing to put being thought of as cool and hip to his friends (or whatever was the guiding motive behind his willingness to release private information of students) above privacy of others, he's probably willing to put profit above privacy and well-being of others. But of course that's already been made clear by his many other actions since then.

I am also saddened that pg time and again praises him for being an example of a good founder. The hacker community should continue giving him as much hell as possible (as most of it does, thankfully), refuse to promote its business (don't put 'Like' buttons on your stuff), don't use Facebook Connect, don't have a FB profile, do not disclose bugs to FB, etc. Don't reward individuals who lack basic conscience.