A new study from Denmark suggests that cellphone cancer fears are unfounded, reports the Associated Press. The study, the largest of its kind, examined nearly half a million cellphone users, many of whom had been using cellphones for up to two decades. Researchers found that there was no link between cancer rates and cellphone use. Despite even less scientific evidence (read: none), people tend to believe that Wi-Fi is harming them as well. Some have been so concerned that they've forced school districts to shut down Wi-Fi networks or have banned Wi-Fi on college campuses because they liken the signals to secondhand smoke.