Google has responded to a U.S. congressman's series of questions about its privacy practices, with the company defending its use of consumer data.

Representative Joe Barton, a Texas Republican, sent a letter to Google Chairman and CEO Eric Schmidt Dec. 12, after privacy groups raised questions about the implications of Google's US$3.1 billion acquisition of online ad server DoubleClick.

During an earlier meeting with Schmidt, Barton had "voiced concern regarding the potential consumer protection and privacy implications of the merger," Barton said in his letter. "I believe Google's participation in our research into and consideration of the consumer protection implications of a merger of any online search engine and any behavioral or targeted advertising firms is vital to crafting sound national policy."

In response to Barton's questions about the privacy implications of the merger, Google repeated its calls for Congress to pass a national privacy law that would create a "uniform framework for privacy."

"Concerns about online privacy cannot be solved by one company alone," said the Google letter, by Alan Davidson, the company's head of U.S. public policy. "Moreover, both technologies and best practices for protecting privacy are changing rapidly. We therefore encourage you and your staff to ask these questions of other providers of online services."

Barton, ranking minority member of the House Energy and Commerce Committee, had asked Google to respond to his letter before Dec. 18, about when the U.S. Federal Trade Commission was expected to complete its examination of the antitrust implications of the merger. Google's response was dated Friday, one day after the FTC announced it would not block the DoubleClick acquisition. Google hosted Barton's staff at its headquarters Wednesday and Thursday, however.

The FTC approval is the last U.S. hurdle for the merger; the European Union is still reviewing it.

Barton's letter asked several questions about Google's privacy practices, including how long Google retains search queries, e-mail drafted on Google's Gmail service and Web histories. Barton also asked why Google needed to retain data.

The IP (Internet Protocol) addresses associated with search queries will be partially deleted after 18 months, as Google previously has announced, the letter said. In other services, such as Gmail and Google Web History, the privacy preferences are customized by individual users, the letter said.

The IDG News Service is a Network World affiliate.