Ukrainian authorities say they have shut down a popular file-sharing website, saying it violated copyright laws.

Interior Ministry Spokesman Volodymyr Polishchuk said Wednesday that Ex.ua was closed after complaints from Microsoft, Adobe and other companies.

Google, Facebook and other big tech companies are jointly designing a system for combating email scams known as phishing.

Such scams try to trick people into giving away passwords and other personal information by sending emails that look as if they come from a legitimate bank, retailer or other business. When Bank of America customers see emails that appear to come from the bank, they might click on a link that takes them to a fake site mimicking the real Bank of America's. There, they might enter personal details, which scam artists can capture and use for fraud.

Twitter CEO Dick Costolo sought to calm the global outrage over the company's new country-by-country censorship policy, complaining in part that the issue is being treated with the same kind of shorthand that has made Twitter popular.

Speaking at the All Things D conference on Monday, Costolo repeated the company's justification for the policy change it announced last week: By taking down tweets only in the country where Twitter believes they may have violated local laws, it is making sure the maximum 140-character-long messages are still available to the rest of the world.

A German appeals court has upheld a decision prohibiting Samsung Electronics Co. from selling two of its tablet computers in Germany, agreeing with Apple Inc. that they too closely resemble the iPad2.

The Duesseldorf state court ruled Tuesday that neither the South Korean company's Galaxy Tab 10.1 nor the Galaxy Tab 8.9 could be sold in Germany because they were in violation of unfair competition laws.

U.S. officials are deploying "the latest tools" to keep cyberspace safe for commerce and protect the US information infrastructure, Homeland Security Secretary Janet Napolitano said.

Napolitano, speaking at the National Press Club, emphasized that homeland security and U.S. economic security "go hand in hand."

NASA is seeking friends for a new game the U.S. space agency launched on Facebook.

The online game, Space Race Blastoff, tests a player's knowledge of the space program with multiple-choice questions. Players can compete against others or play solo.

New Jersey's largest city must produce a list of documents related to a $100 million pledge to its public schools from Facebook founder Mark Zuckerberg, a judge ruled Friday.

The ruling stemmed from a lawsuit brought by the American Civil Liberties Union on behalf of a group representing Newark schoolchildren that is seeking more transparency about the donation. The Associated Press and other news outlets also have made such requests.

Thailand is welcoming Twitter's new policy to censor tweets in specific nations where the content might break laws.

Technology minister Anudith Nakornthap said Monday the new policy was a "constructive" development. The Southeast Asian country routinely blocks websites with content deemed offensive to the Thai monarchy.

A look at results from selected companies in the video games business:

Jan. 9: GameStop Corp., the world's largest video game retailer, reports nearly flat sales for a nine-week holiday period that ended on Dec. 31. Sales of game software rose but sales of game consoles and other hardware slid. The company backed its fourth-quarter and full-year earnings guidance.

The shadowy online hackers group Anonymous blocked access to the websites of the Mexican Senate and the Interior Ministry Friday to protest a proposed law to fine people who violate copyright online.

The proposal, from conservative senator Federico Doring, is widely seen as the Mexican version of SOPA -- the U.S. Senate and the Stop Online Piracy Act that Wikipedia and other Web giants have denounced as a threat to Internet freedom.