Facebook says the world wants to be "more open and connected," and 400 million people seem to agree. But complaints about privacy have led to promises about new controls, a pattern Facebook watchers have seen before. A week ago, Farhad Manjuoo of Slate.com predicted that CEO Mark Zuckerberg would respond to such concerns with a letter admitting that Facebook has "missed the right balance" between sharing information more freely and sharing too much. Today, Zuckerberg issued a letter saying, "We have heard the feedback…"