Facebook users are becoming more private, according to a study released last week.

An increasing number of social network users are tightening up their privacy settings, "pruning" their personal profiles and unfriending people, according to the US study by the Pew Internet & American Life Project.

About two-thirds of internet users use social networks, and a huge percentage of them are getting more strict about letting others access their Facebook, Google+ and Twitter pages.

The Pew telephone survey of 2,277 American adults found that 63% of social network users have deleted friends, 44% have deleted comments that friends made on their profiles and 37% have taken their names off photos that had been tagged to identify them.

The study found that 67% of women have deleted people from their network, while 58% of men have done the same.

Pew said 67% of women say they set their social networking privacy controls at the highest setting, while 48% of men said the same.

Regardless of gender, 58% of social networking users say their profile is set so only friends can view it. Another 19% allow friends of friends to see their profile and 20% set their profiles as public.