Are Google's Behavior-Based Ads a New Privacy Concern?

Google's new interest-based advertising may lead to increased revenues for the search company, but privacy advocates have a list of new concerns for Google. Yahoo and other search-engine companies already use a variant of this sort of advertising, called "behavioral targeting," in order to increase their advertisers' chances of success. However, now that Google has entered the mix, privacy advocates fear they have more to worry about.

Google has raised privacy concerns with its newly launched interest-based advertising, which displays ads based on users' previous searches and page views. Also known as "behavioral targeting" or "online behavioral targeting," the method has privacy advocates up in arms over Google collecting massive amounts of user data.

While search engines use this type of technology, the fact that Google is now testing it has raised additional privacy concerns from those that see the search engine giant as already collecting too much personal information on its users. However, some others are defending Google, saying the company already has controls in place to control how personal data is used and collected.

The new Google advertising system, currently in beta, links "categories of interest" to the user's browser, allowing targeted ads to appear even when the user is looking at a page totally unrelated to the ad's subject matter. For example, someone who has spent months looking at pages about mini-notebooks will find ads for mini-notebooks appearing even when they're on a site unrelated to PCs.

Google's search rival Yahoo has already introduced its own application based on behavioral targeting, called Search Retargeting, which focuses display advertising based on users' search histories. Search Retargeting, announced on Feb. 24, was anticipated by analysts as having the potential to draw massive privacy protests, but pushback from privacy advocates so far seems minimal.

For years, search engine companies have struggled to reassure the public that whatever information they collect is not being abused. This has led to much hand wringing about how long they should retain user data.

On Dec. 17, Yahoo announced that it could cleanse its system of user log data within 90 days. By contrast, Google has publicly stated that its data retention time is nine months.

Nicole Wong, deputy general counsel for Google, argued in a blog posting on March 11 that the privacy policy behind the company's interest-based ads provided "meaningful transparency and choice," with the company drawing a line at data-mining potentially sensitive categories for ad revenue.

"To provide greater privacy protections to users, we will not serve interest-based ads based on sensitive interest categories," she wrote. "For example, we don't have health status interest categories or interest categories designed for children."

Users will be able access the individual interest categories associated with their browser via a tool called Ad Preferences Manager and add or delete specific ones.

"Access to the profile is something we've been promoting for years, and what we've been hearing from companies is that it would be too difficult for consumers; Google has essentially disproved that," Alissa Cooper, chief computer scientist for the Center for Democracy and Technology, said in an interview. "On the ad profile and ad access front, they've moved the ball forward."

Cooper also believes, though, that Google could stand to buttress its privacy protection in other areas - particularly with regard to its cookies. At the moment, Google users have the ability to delete their interest-based advertising cookie for the AdSense partner network, curtailing Google's tracking; but there's a catch.

"The cookie is only specific to the ads that Google is serving," Cooper said, which still leaves users potentially open to other search engines that utilize cookies for behavioral tracking.