Wednesday, August 13, 2008

Flash cookies - good and bad

I delete my cookies once a month or so. I do not care my session experience for more than month, and also my tastes change over the time. I am watching Olympics and visit sports website frequently now a days, but I do not want to see any ads and popup ads for fitness in coming weeks or after month. I deleted cookies, and visited some other website. I got similar ads after deleting cookies.

It is sure that both the websites are using same advertising company. However there can only be two reasons why I got the same ad. That advertiser has nothing else to show, or he tracked my behavior even after my cookies are cleared. So I did little research and found that there are some other cookies allowed by flash which comes installed in all browsers as part of Adobe's business partnership with HP and Dell computers.

Those cookies may be giving me better user experience in filling forms or giving contextual user experience, but why did it allow the tracking websites without telling me? That is also 100KB per website compared to 4KB browser cookies. Some bloggers were even saying that some websites are using flash cookies and restoring regular cookies from them, since most users are deleting regular cookies. I am not sure how much truth is in those fears, but I deleted all my old websites and allowed only few trusted sites like youtube, amazon and google. I googled around and found that I can change my settings.

Visit the control panel for flash related global storage settings and set the limits or disable all websites to save some information.
Visit the page 
Controlling storage for visited websites
 and see the websites that have already have saved information, delete the ones you do not want or delete all.

Flash cookies explained
Local Shared Objects
Local Shared Objects(LSOs) details from wikipedia
Webserver cookies threaten privacy

No comments: