Google announced today that its proposed $3.1 billion acquisition of Internet advertising company DoubleClick has become official. Although the company announced its intentions last April, the deal had to first undergo scrutiny from U.S. and European regulators. The FCC approved the merger in December, while European regulators closed their investigation today. The New York Times reports that rivals such as Yahoo and Microsoft had opposed the acquisition, worrying about an increase in Google's already dominating market share. Also, some consumer groups were concerned about the enhanced access to user data that Google will gain as a result of the merger.