Six years after it was created in a dormitory at Harvard, Facebook reported on Wednesday it now has 500 million members. The social networking site has grown rapidly, doubling in size from a year ago. The company reported more than 30 billion photographs, links to Web sites and news articles are shared through the site, and its members collectively spend roughly 700 billion minutes there each month. But the website has faced a few setbacks during its rise to the top, including intense scrutiny over changes to its site that encouraged members to make more information about themselves accessible to anyone on the Internet. A recent survey by the American Customer Satisfaction Index showed that user satisfaction with Facebook stood at 64 on a 100-point scale, which placed it in the bottom 5 per cent of the companies covered in the index.