In court papers filed on Friday, Google said the demand by the Department of Justice for web search data could undermine public trust in Google's efforts to ensure users' privacy as well as expose its trade secrets, reports the Washington Post. Google's response (pdf), filed in a California federal court, argued against a DOJ motion to force Google to comply with the original subpoena.

DOJ says the data will help it determine how much inappropriate content is accessible to children on the web and how well filters are in screening out such material in comparison with the 1998 Child Online Protection Act, which has not been enforced because of a 2004 Supreme Court decision blocking its implementation.

The American Civil Liberties Union, which was among those challenging that law, said in statement regarding DOJ's motion, "The government is not entitled to go on a fishing expedition through millions of Google searches any time it wants, just because it claims that it needs that information."

However, CNET writes, the ACLU has in turn said if the government is granted the Google information, the ACLU would then have to subpoena Google, despite having "no need or desire to obtain any of this information from Google." But if the government gets the information, it would have little choice, it said.

The "threat" of a potential subpoena from the ACLU could complicate the DOJ's attempt to convince U.S. District Judge James Ware to grant the DOJ's request.