• by Wendy Davis , Staff Writer @wendyndavis, February 25, 2011

For at least the fourth time since last January, Google is facing questions regarding its views on privacy.

This latest incident stems from the company's Doodle-4-Google contest for students, which allows students to win prizes including a $15,000 scholarship. This year, the company initially asked the entrants, who ranged from kindergarten students to seniors in high school, for the last four digits of their social security numbers. Google said it did so because it wanted to keep better track of entries, since not all of the students attended schools that had registered for the contest.

When the move came to light, people immediately questioned why Google would collect that type of sensitive information -- and from children, no less. Among others, Reps Ed Markey (D-Mass) and Joe Barton (R-Texas), co-chairmen of the House Bi-Partisan Privacy Caucus, said they were "deeply disturbed" by the news.

When it comes to Google's core search business, the company has a fairly good history of protecting users' privacy. Five years ago, Google was the only search engine to oppose a federal subpoena that sought information about people's online searches.

But that concern about privacy doesn't always seem to extend beyond search. Consider, when Google launched Buzz last February it revealed information about the names of users' email contacts by default. In May, the company admitted that its Street View cars intercepted data from WiFi users. And last January, Google acknowledged that its toolbar mistakenly collected data about the sites users visited even after they opted out.

While it doesn't seem likely that Google collected any of this data for sinister reasons, the incidents at least indicate that privacy isn't always a priority for the company. And that's a problem given Google's ambitious plans to enter spaces like voice, digital books and other areas far removed from search.