Flash: Similar to the HTTP cookie, a Flash cookie is a Local Shared Object that can be used to track users, assign unique user ids, and/or save application parameters. An August 2009 study by the Social Science Research Network found that 50% of websites using Flash were also employing Flash cookies. However, privacy policies rarely disclose the presence of Flash cookies, and user controls for effectuating privacy preferences are lacking. Its a relatively simple tactic to employ; a website need not even have deep flash functionality. For example, it is possible to embed a small 1x1 pixel transparent background flash file somewhere out of the way on a page - and all of the programming features, including access to the Local Shared Object will be available. Most surprisingly is that it took 9 years for this tactic to be discussed by the general public, considering that versions of this existed previous to the Local Shared Object and has long been a staple in subverting cookies. |
