Reception   According to  comScore , Facebook is the leading social networking site based on monthly unique visitors, having overtaken main competitor MySpace in April 2008. [185]  ComScore reports that Facebook attracted 130 million unique visitors in May 2010, an increase of 8.6 million people. [186]  According to  Alexa , the website's ranking among all websites increased from 60th to 7th in worldwide traffic, from September 2006 to September 2007, and is currently 2nd. [187]   Quantcast  ranks the website 2nd in the U.S. in traffic, [188]  and  Compete.com  ranks it 2nd in the U.S. [189]  The website is the most popular for uploading photos, with 50 billion uploaded cumulatively. [190]  In 2010,  Sophos 's "Security Threat Report 2010" polled over 500 firms, 60% of which responded that they believed that Facebook was the social network that posed the biggest threat to security, well ahead of MySpace, Twitte...