Despite some skepticism and fears, a growing number of educators are using social-networking websites such as Facebook and Twitter to help students learn. One high-school principal in New Jersey calls cellphones "mobile learning devices" and encourages their use in communication and learning. "The Internet as we know it is the 21st century," Eric Sheninger said. "It is what these students have known their whole lives. They're connected, they're creating, they're discussing, they're collaborating."