While no campus is perfectly safe, BYU is pretty close. Without the problems brought on by alcohol and drugs,
crime stats stay remarkably low. Granted, a laptop computer left unattended in a hallway may not be there when you get back, but with a little common sense, you can easily go through your BYU career without any major problems (security-wise, at least).
Few campuses in America can boast the safety that BYU does. The Safewalk program is well designed and set up to make sure that students get home from campus safely late at night. BYU also regularly runs awareness programs on everything from water usage to driving safety. The dorms on campus automatically lock at 11 p.m., after which only residents can enter. Fellow students are friendly and look out for one another. It's the BYU way.