This study uses Protection Motivation Theory (PMT) as a theoretical framework to empirically test why people back up data on their personal computers. The theory was tested using 112 surveys collected using both paper and online data sources. The findings show that computer self-efficacy and response efficacy both positively affect the backing up of data, while perceived security vulnerability and perceived security threat both negatively affect the backing up of data. The results and implications of these findings suggest further research is necessary to fully understand the relationship between security threats and protective behaviors.