Protect Your Online Privacy: Say NO to Ad Cookies

by Ari Herzog on Jun. 10, 2010 · 12 comments


Cookie Monster poses at Children's Hospital Boston

Every time you visit a new website you run the risk of a cookie (a text file with aggregate interest- or activity-based behavioral information, usually sparked by submitting an online form) being secretly placed in your browser. Sometimes the website has a privacy policy that tells you this, sometimes it doesn’t. Over time, if you never flush the cookies out of your system, they build up to the point that when you visit a website you don’t think you visited before, the cookie is activated and a message like, “Welcome back, Charles!” appears.

Facebook and Yahoo Mail account holders, for instance, may be exposed to banners or other advertisements. Real-time analytics are run on who you are, the type of computer and operating system you use, the geographical proximity of your IP address, and other non-personal characteristics that paint a somewhat accurate picture, when combined with other cookies, on your likes and dislikes. When you buy a weed whacker on eBay, the cookie remembers. When you hover your mouse over an ad about a video, the cookie remembers. Every time you web surf and click link to link to link, cookies fade in and out of dominance.

It is hard to browse the graphical web without cookies — and nine times out of ten, they are harmless. BlueKai aggregates your shopping habits, Criteo tries to hone you back in when you don’t buy something, MediaMath‘s algorithms work behind the scenes of display ads.

But just because a cookie is in your computer collecting data on your browsing experience doesn’t mean its existence is necessary to browse.

National Advertising Initiative logoThe National Advertising Initiative was formed in 1999 and works cooperatively with third-party advertisers and the general public like you to raise awareness on what is being collected and stored by cookies. If you want to remove a cookie from your computer browser, click this link and opt out of whatever advertising networks you want.

When I clicked the link moments ago, the tool identified the cookies in my browser that matched the advertisers in its cooperative database and allowed me to select individual cookies or all cookies to stop recording my online movements.

Cookies that were active in my system

After scrolling to the bottom of that page, I clicked the “Select All” button and then the “Submit” button. NAI then showed me a result page and then a confirmation page.

Result page after cookie removal

To be fair, the cookies were not removed but NAI inserted its own cookie to tell the other cookies I opted out. If I clear my browser cookies, I would need to run the program again. It might be something to consider, especially if you are paranoid about too many companies knowing about your browsing habits.

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{ 12 comments }

Mary E. Ulrich June 10, 2010 at 5:42 AM

Thanks, I just “selected all” and opted out. Feels as good as taking a morning shower.

Ari Herzog June 10, 2010 at 8:47 PM

Glad to refresh you.

MJ June 10, 2010 at 5:55 AM

Hi Ari,

I just wanted to add on your great article…
The NAI Consumer Opt Out Protector Add-On for Firefox is a great complementary tool for mozilla firefox users…

It has been my habit to set-up my browser add-ons right after I installed it, and I just added the NAI add-on to my list of good ad blocking tools…These are really handy and helps us keep track of our privacy settings online…

Ari Herzog June 10, 2010 at 8:47 PM

Thanks for the info!

John Soares from Time Management Techniques June 10, 2010 at 2:57 PM

Ari, I have PC Tools Spyware Doctor set to run an automatic scan every evening. It almost always finds ad tracking cookies, which I have it delete.

Seems like we’d have to deal with the cookies settings anew after every time we clear ‘em.

I’ll likely take my chances and continue to only visit good neighborhoods. And I’ll buy my weed whacker new at Home Depot!
.-= From John Soares @ Time Management Techniques to you: The Importance of Free Time Alone =-.

Ari Herzog June 10, 2010 at 8:53 PM

Good point on doing things over and over. Maybe this cookie can be a persistent one. Regardless, you don’t get ad tracking cookies here, just the good ones.

Micah June 10, 2010 at 3:30 PM

This is such a good article. People really have no idea the kind of information others can see just by looking at certain sites. Thanks for the post.
-Micah

Ari Herzog June 10, 2010 at 8:53 PM

Thanks for sharing your thoughts.

Jeet June 11, 2010 at 5:25 AM

But it would have been better if there was a more ‘permanent solution’ other than blocking all cookies or selectively whitelisting sites, cause as u have said, this needs to be done every time the cookies get cleared. I have kept my firefox settings to clear the cookies every time i close the browser for security reasons, so this method would be a fail for me.
.-= From Jeet to you: Sitepoint mods are sleeping =-.

Ron June 11, 2010 at 9:15 AM

Ari, thank you for yet another very interesting article. I had no idea stored cookies were able to continue to track my browsing and surfing habits. Though I have nothing to hide, I just am very concerned this information could fall into the wrong hands and be used against me. Ill have to look into the NAI tool and see how it works for me.

Fred H Schlegel June 11, 2010 at 12:24 PM

We are in such need of better tools to manage how information is leaking during everyday activities like browsing and calling. Managing cookies can become a full time job and so by default we let them gather whatever they want. A true solution that lets you manage what companies can gleam from cookies would be welcome.
.-= From Fred H Schlegel to you: How Do You Value Relationships? How Does Facebook? =-.

Patrick July 11, 2010 at 10:42 AM

Every Cookie created has a definite age ranging from few hours to sixty days at maximum,which is set at the time of cookie creation by its creator.Ari,I bet that many of us do not know that Google uses information from these stored Cookies to target ads to the web pages you visit.This is new and is known a behavioral ad targeting.But in spite of all this stuffs you must always clean cookies (especially ad cookies) in order to protect your privacy.I use a tool named CCleaner for this.It is very good in deleting all your Internet Traces.
Patrick recently wrote How to Trace Mobile Phone number in USA Canada and Caribbean IslandsMy Profile

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