Smartphones are proliferating among adolescents, and so is cyberbullying. That’s particularly worrisome due to its potential contribution to the No. 2 cause of teen death: suicide. About 26.3 percent of the middle- and high-school students who responded to a nine-school survey indicated that they’d been bullied in each of the eight years the poll was taken, the Cyberbullying Research Center found. That percentage stood at about 18.8 percent back in May of 2007 but climbed to around 34 percent by February of last year.