Venture capitalist Bill Gurley had a warning for tech investors at the Goldman Sachs Technology and Internet conference on Thursday. He thinks that private tech companies with unrealistic, sky-high valuations aren't being properly audited. “Stop cramming money into private companies,” Gurley, a Benchmark partner, told the audience, Forbes' Ellen Huet reported. Here's Huet, who attended the event: "The opportunity to invest in a private round of a popular company is getting so hyped that some startups are inviting investors in, Gurley said. He told an anecdote about a friend of a friend who 'got a phone call where they were invited to participate in a private round,' he said. 'And I just thought the notion of the invitation is so Madoff-esque, right? … This is a party where everyone has been invited. It’s just not that hard to get access.'" Gurley specifically warned against overspending on low-margin, on-demand, same-day delivery startup...