Furthermore, Google's argument that the IP addresses stored in the YouTube logging database represent personally identifiable information is at odds with the company's previously stated views on that issue, according to Rotenberg. In cases such as its dispute with the DOJ, Google argued that IP addresses and the other search-related data was practically useless in helping anyone to identify an individual, Rotenberg said. Stanton made the same point in his July 2 ruling in favor of Viacom.

"There is a clear contradiction in Google's position, that they will assert privacy interests when it is in their favor to do so," Rotenberg said.

Jeff Chester, executive director of the Center For Digital Democracy, a not-for-profit advocacy group in Washington, agreed with Rotenberg that privacy advocates should be equally critical of Google as they are of Stanton's decision on the YouTube viewing data.

"Google is collecting huge amounts of information about YouTube users in order to expand its targeted advertising business," Chester said. Pointing to Google's recent acquisition of DoubleClick Inc. as a marker of the company's aspirations, Chester asked, "Why is Google—and almost every other leading broadband video provider—tracking and analyzing our online viewing habits?" Chester asked. The goal clearly is to deliver highly targeted marketing campaigns based on the Internet viewing habits and search queries of individual users, he said.

While companies such as Google have argued in the past that the data they collect isn't personally identifiable, it is "antiquated" to think of personal data as simply consisting of information such as names, birth dates, street addresses and Social Security numbers, Chester said. In the online world, IP addresses, Web-site cookies and other tracking data can help narrow down a person's identity more than may typically be assumed, he added. Some of the tracking methods being used by Google and other online companies "make Nielsen's look like it was developed in the Stone Age," Chester quipped.