What is this: //http:ad.doubleclick.net/adi/N866.104?

[Roy]

I am a long-time user of Yahoo Finance, but recently I an having a LOT of problems going back and forth using the page forward/back arrows going from lets say a company's profile page and competitors page it won't let me. When I right-click on one of the arrows, it only shows a long list of the message listed above. Today, after I cleared my browsing history, I ran into the same problem - not being able to back and forth between Yahoo Finance pages, but this time when I right-clicked on the back arrow I saw a long list of the following message:
//http:view.atdmt.com/CNT/iview/4360301. What is going on??????

[Ed Atun]

It is bad news (but not dangerous). doubleclick tracks your online activities. They sell what they find to other companies. They leave tracking cookies on your hard drive. Delete them. (search your computer for Cookies and you will find them).