UCSD students are notorious for never thinking about safety and security—La Jolla is one of the quietest and safest cities in San Diego County. Security on campus is excellent;, and there are phones spread around campus that have a direct line to the police station, good lighting at night, and CSOs (community service officers) who will walk you anywhere on campus, all night long. For the first couple of months, UCSD can be intimidating, especially at night. Still, hardly anyone has had problems with security.
There has been a small amount of typical University crime reported at UCSD, such as petty theft, especially wallets and bikes, but generally UCSD is incredibly safe. Every year, there are reports of sexual assault, so keep an eye on your friends, particularly at parties or where there is a lot of alcohol. Some students even confess to never locking their dorm or apartment doors. The UCSD police station has done such a good job at keeping campus safe that many students forget to think about their safety at all.