Digital tools can be used for all steps of conflict prevention: early warning, prevention measures, evaluation. In order to do successful prevention we need to create reliable early warning signals, impactful prevention measures, and evaluations of projects which lead to the non-occurrence of negative developments. How can we avoid negative unintended consequences and adhere to the principal of Do No Harm when using such tools for prevention purposes, e.g. data protection and privacy issues, protecting vulnerable groups and avoiding biases when collecting and analysing data (bias in, bias out/garbage in, garbage out)?