A political controversy over deleted documents and conflicts of interest among online rights groups have drawn recently a lot of criticisms to the proposed Google-DoubleClick deal.

This and other issues made legislators from the United States, the European Union and Australia to put the deal under their inspection.

As the United States are concerned about privacy issues, the European Union had concentrated on how the $3.1 billion acquisition would impact competitiveness in the online advertising arena. Also, an EU civil liberties panel has asked Google and online advertisement company DoubleClick to testify in matters of privacy in January 21 or January 31.

The U.S. Senate held similar hearings in September, this year. The EU and the U.S. Federal trade Commission intend to conclude on their investigations into the deal by April 2.

Representative Joe Barton, a ranking Republican on the House Energy and Commerce Committee, has asked Google to answer to 24 questions on privacy practices and policies related to the company's proposed acquisition of online ad company DoubleClick.

David Drummond, the senior vice president of corporate development and chief legal officer at Google has assured the U.S. Senate in September that privacy is a primary issue for the company as Google’s business depends on it.