Google has completed its $12.5 billion purchase of device maker Motorola Mobility in a deal that poses new challenges for the Internet's most powerful company as it tries to shape the future of mobile computing.

The deal closed Tuesday, nine months after Google Inc. made a surprise announcement that it wanted to expand into the hardware business with the most expensive and riskiest acquisition in its 14-year history. The purchase pushes Google deeper into the cellphone business, a market it entered four years ago with the debut of its Android software, now the chief challenger to Apple Inc.'s iPhones.

Regulators are examining whether Morgan Stanley, the investment bank that shepherded Facebook through its highly publicized stock offering last week, selectively informed clients of an analyst's negative report about the company before the stock started trading.

Rick Ketchum, the head of the Financial Industry Regulatory Authority, the self-policing body for the securities industry, said Tuesday that the question is "a matter of regulatory concern" for his organization and the Securities and Exchange Commission.

Nintendo's Shigeru Miyamoto, creator of Super Mario Bros, Donkey Kong and other hit video games, on Wednesday won Spain's prestigious Prince of Asturias Prize.

The jury praised the 59-year-old Japanese game designer for turning video games into "a medium capable of bringing people together regardless of sex, age or social or cultural status."

Cyber criminals are cranking out new weapons at a brisk pace, tailoring malicious software for a spectrum of gadgets including smartphones, tablets, and Macintosh computers, a security firm said.

A "threats report" released late Monday by McAfee showed that the number of new pieces of malicious code, or "malware," targeting Windows machines in the first three months of this year was the highest in four years.

YouTube celebrated its seventh birthday by saying it has hit fresh milestones in terms of its offerings and the amount of time spent on the video-sharing website.

"Today 72 hours of video are uploaded to the site every minute," the Google-owned website said in a blog post Sunday.

Microsoft's upcoming Windows 8 series -- featuring an upgraded cloud computing service -- marks a "rebirth" of its operating systems, chief executive Steve Ballmer said Tuesday.

Ballmer described Windows 8 as the "deepest, broadest and most impactful" Windows software ever created by the U.S. tech giant, after the current Windows 7 sold at unprecedented rates to businesses.

The U.S. Justice Department on Monday acknowledged an intrusion in its computer network as the notorious hacker collective Anonymous claimed to have obtained large amounts of data from it.

"The department is looking into the unauthorized access of a website server operated by the Bureau of Justice Statistics that contained data from their public website," a statement sent to Agence France Presse said.

A U.S. judge on Monday said a Kodak patent allegedly infringed upon by Apple and Blackberry-maker Research In Motion (RIM) was not valid, dealing another blow to the struggling photography pioneer.

The preliminary ruling by International Trade Commission Judge Thomas Pender holds that neither Apple nor RIM infringed on Kodak's intellectual property by using the technology in some of their gadgets.

The European Union says Google Inc. must in "a matter of weeks" outline steps it is willing to take to ease concerns about alleged abuses of its dominant position in the online search market.

EU antitrust chief Joaquin Almunia said Monday that after a 1 ½ year investigation it had pinpointed four specific areas of concern and insisted the problems needed to be dealt with swiftly.

Alibaba, China's top e-commerce player, will re-purchase a 20-percent state in itself from U.S. portal Yahoo! for at least $7.1 billion, the companies announced Sunday.

"At the minimum price and assuming the initial repurchase of the full 20% stake, Yahoo! would receive from Alibaba consideration of approximately $7.1 billion, composed of at least $6.3 billion in cash proceeds and up to $800 million in newly-issued Alibaba preferred stock," the firms said in a statement.