"Shortly after leaving the University of Oklahoma , DeMarco Murray was convinced by a marketing expert to join Twitter.

During a radio interview this week the Cowboys running back admitted that even though he was skeptical at first, he's enjoying his time on the social networking site. The only negative can be some unruly fans.

San Francisco 49ers punt returner Kyle Williams witnessed the extreme side of sites like Twitter following Sunday's NFC Championship Game. Williams, whose two muffed punts led to the New York Giants scoring 10 points in the final quarter, received death threats because of his costly mistakes."