Attitudes towards Client-Side Scanning for CSAM, Terrorism, Drug Trafficking, Drug Use and Tax Evasion in Germany

In recent years, there have been a rising number of legislative efforts and proposed technical measures to weaken privacy-preserving technology, with the stated goal of countering serious crimes like child abuse. One of these proposed measures is Client-Side Scanning (CSS). CSS has been hotly debated both in the context of Apple stating their intention to deploy it in 2021 as well as EU legislation being proposed in 2022. Both sides of the argument state that they are working in the best interests of the people. To shed some light on this, we conducted a survey with a representative sample of German citizens. We investigated the general acceptance of CSS vs cloud-based scanning for different types of crimes and analyzed how trust in the German government and companies such as Google and Apple influenced our participants' views. We found that, by and large, the majority of participants were willing to accept CSS measures to combat serious crimes such as child abuse or terrorism, but support dropped significantly for other illegal activities. However, the majority of participants who supported CSS were also worried about potential abuse, with only 20% stating that they were not concerned. These results suggest that many of our participants would be willing to have their devices scanned and accept some risks in the hope of aiding law enforcement. In our analysis, we argue that there are good reasons to not see this as a carte blanche for the introduction of CSS but as a call to action for the S&P community. More research is needed into how a population's desire to prevent serious crime online can be achieved while mitigating the risks to privacy and society.