The share of adult Internet users who have a profile on an online social network has more than quadrupled in the past four years, from 8 percent in 2005 to 35 percent now, according to a new Pew Internet study of adults and social networks. Not surprisingly, use of social networks still remains much heavier among younger adults, with 75 percent of those aged 18-24 using social networks compared to 7 percent of those 65 and older. (Full report in PDF.)

Photo of Bob Ambrogi Bob Ambrogi

Bob is a lawyer, veteran legal journalist, and award-winning blogger and podcaster. In 2011, he was named to the inaugural Fastcase 50, honoring “the law’s smartest, most courageous innovators, techies, visionaries and leaders.” Earlier in his career, he was editor-in-chief of several legal publications, including The National Law Journal, and editorial director of ALM’s Litigation Services Division.