©IDG Communications, Inc. Photo contributed by Matthew Mikaelian.
Despite promising that they won’t reveal users’ personal data, some of the most highly trafficked Web sites transmit usernames, email addresses, addresses, and even birth dates to ad networks and other third parties, a new study confirms
For the study, “Where Everybody Knows Your Username,” Stanford researcher Jonathan Mayer looked at 185 popular sites that collect registration information about users. He found that 61% of those sites “leaked” people’s usernames or user IDs to one or more outside companies. Much of the leakage appears to be inadvertent; frequently it results from including usernames in the referrer headers, and other design flaws.