SHANGHAI (Reuters) - When it comes to China, Facebook should consider itself forewarned. Cracking the world's biggest Internet population might seem an obvious ambition for the social networking giant as it trumpets its global growth before a $5 billion initial public offering, but the chances it will succeed look slim. Facebook said last week it was contemplating re-entering China, the world's second-biggest economy, after being blocked nearly three years ago. But its offering would likely face intense competition, political meddling and little commercial success. ... read more..