Twitter, Tumblr and Pinterest alerted affected users via email.
Few days back Apple was attacked by Hackers.
China has been accused of mounting a widespread, aggressive cyber-spying campaign for several years, trying to steal classified information and corporate secrets and to intimidate critics.
U.S. cyber security firm Mandiant reported over the weekend that it has uncovered evidence that the Chinese military is behind a slew of cyber attacks on U.S. businesses. The White House said it has repeatedly raised concerns about Chinese cyber theft with Beijing."
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