A widespread spam attack linking to malware has broken out on Twitter, according to the security firm Sophos.

Dropbox's ongoing investigation into a possible security breach has not produced any evidence that its systems have been infiltrated, according to an update Friday to the company's user forum.

Pinterest has locked an undisclosed number of user accounts as a result of a spam outbreak, the company confirmed in an email on Friday.

Skype, a division of Microsoft, confirmed on Monday that a glitch in its software has led to instant messages being shared with unintended parties.

Twitter has issued its first report about the requests it has received from various governments for information about users.

Internet experts are divided over whether technology companies will cooperate in the coming decade with repressive regimes that seek to limit or monitor individual Internet use, according to a study released Monday by the Pew Research Center and Elon University.

Twitter released a report on Monday about the user information requests it has received from governments this year and how it responded to them.

LinkedIn has been hit with a potential class-action lawsuit alleging it failed to meet "industry standard" security practices in connection with a massive data breach earlier this month, according to court documents.

Facebook has acquired Face.com, the facial recognition software company whose products power Facebook's photo tagging suggestions, according to a blog post.

Facebook has started promoting security tips at the top of each user's home page, with a link to information about scams, passwords and how to stay safe on the social network.

Voting on Facebook's proposed changes to its privacy policy concluded Friday morning Pacific time, with voters delivering a strong rebuke of the proposed changes but falling far short of the turnout the company required to consider the vote binding.

When Microsoft slayed the notorious botnet Rustock, which had been sending as much as 40 percent of all spam worldwide, in March 2011, it forced the volume of spam into a decline from which it has never fully recovered.

Facebook is conducting a massive user referendum this week, asking its 900 million-plus users to approve or reject changes to its privacy policy that it first proposed on May 13.

A McAfee study of PCs around the world found that 17 percent had no antivirus protection, and the U.S. outpaced the average with 19 percent of PCs unprotected.

PC malware had its "busiest quarter in recent history," according to McAfee's quarterly security report released Wednesday.