Every day, Wall Street analysts upgrade some stocks, downgrade others, and "initiate coverage" on a few more. But do these analysts even know what they're talking about? Today, we're taking one high-profile Wall Street pick and putting it under the microscope...Shares of copper and gold miner Freeport-McMoRan (NYSE: FCX) were sliding this morning, but don't be fooled: The news on Freeport today is good, not bad.Yesterday evening, fellow mining company and Freeport partner in Indonesian copper mining Rio Tinto (NYSE: RIO) said that it is in discussions to sell its stake in Indonesia's Grasberg copper mine.