Remember the dot com debacle of a decade ago? Well, it’s back, this time in the form of Facebook. Since its high-profile public offering last May at over $38/share, FB is now down to about $18/share. Management is finding that running a public company is very different than one privately held, as people variously blame Mark Zuckerberg (or not), CFO David Ebersman, lead IPO underwriter Morgan Stanley, and even the NASDAQ stock exchange. The real problem, of course, is that Facebook went public even as its business model desperately searches for new revenues. Let’s just hope they don’t pull a Digg and fatally redesign the whole site in response.