A recent study by researchers at CSIRO, ICSI, UC Berkeley, and University of New South Wales showed that many free Android VPN apps are not actually secure. The study looked at close to 300 apps, and found that 84% leaked traffic, while 18% didn't use encryption at all. Narseo Vallina-Rodriguez, a scientist at ICSI and IMDEA who is a co-author of the study, was not surprised by the results, and in fact told The Verge that "the shocking fact was that people trust this kind of technology."