The study by the Pew Research Center’s Internet and American Life Project also found that men were nearly twice as likely as women to have posted content online that they later regret. Sixty-three percent of social network users have deleted people from their friend lists, according to the study, up from 56 percent in 2009. Sixty-seven percent of women who maintain a social networking profile said they have deleted friends compared with 58 percent of men.When it comes to privacy, 58 percent of social network users set their profile to private so that only friends can see it. Nineteen percent allow friends of friends to view their profile and 20 percent keep their profile public. Women are significantly more likely than men — by a 67 percent to 48 percent margin — to set their profile to private, the study said. The study found that men are nearly twice as likely as women to have posted updates, comments, photos or videos that they later regret. Eleven percent of social network users say they have posted content they regret with 15 percent of men saying they have done so and just eight percent of women. The survey of 2,277 adults was conducted in April and May of last year and has a margin of error of plus or minus 2.4 percentage points.

Documents obtained by The Wall Street Journal open a rare window into a new global market for the off-the-shelf surveillance technology that has arisen in the decade since the terrorist attacks of Sept. 11, 2001. The techniques described in the trove of 200-plus marketing documents, spanning 36 companies, include hacking tools that enable governments to break into people's computers and cellphones, and "massive intercept" gear that can gather all Internet communications in a country. The papers were obtained from attendees of a secretive surveillance conference held near Washington, D.C., last month.