When Facebook goes public, it's expected to be the biggest initial public offering (IPO) in Silicon Valley history, possibly raising $10 billion on a value of $100 billion. Founder Mark Zuckerberg says, "We don't build services to make money, we make money to build better services." What will that mean to potential investors — especially when Zuckerberg, age 27 — will retain almost total control? Will becoming a publicly traded company necessarily change his style? How will he deal with government oversight, especially overseas? As he sells the personal data of 800 million "friends," will they all stay comfortable or raise more questions about violations of privacy?