SAN FRANCISCO (AFP) – US computer security firm Symantec has said that Facebook accidentally left a door open for advertisers to access profiles, pictures, chat and other private data at the social network. Facebook told AFP that there was no evidence anyone stepped through that door and swiped any information from the accounts of its more than 500 million members. Symantec discovered that certain Facebook applications leaked tokens that act essentially as "spare keys" for accessing profiles, reading messages, posting to walls or other actions. Facebook applications are Web software programs that are integrated onto the leading online social network's...