There's been a steep drop among teens
                                
                                
                                    (Newser) -
                                    Millennials engage in the widest variety of online activities, but older users have some niches of their own, a new Pew Internet study says. Millennials, loosely defined as people aged 18 to 33, are more likely to use social networking, online classifieds, instant messaging, music sites, and "virtual worlds"...