" Smartphone tracking apps exist that allow a person to not only surreptitiously track another person's smartphone location information, but also surreptitiously intercept the smartphone's communications-such as texts, e-mails, and phone calls. This type of monitoring-without a person's knowledge or consent-can present serious safety and privacy risks. GAO was asked to review issues around the use of surreptitious smartphone tracking apps. This report examines (1) how companies are marketing smartphone tracking apps on their websites, (2) concerns selected stakeholders have about the use of tracking apps to facilitate stalking, and (3) actions the federal government has taken or could take to protect individuals from the use of surreptitious tracking apps. GAO identified 40 smartphone tracking apps and analyzed their websites' marketing language. GAO interviewed stakeholders selected for their knowledge in this area, including academics; privacy, industry, and domestic violence associations; and tracking app and other companies. GAO also interviewed representatives of five federal agencies. GAO is not making any recommendations in this report. The Federal Trade Commission, the Department of Health & Human Services, and DOJ reviewed a draft"