Progress in precision medicine is being achieved through the design of clinical trials that use genetic biomarkers to guide stratification of patients and assignation to treatment or control groups. Genetic analysis of biomarkers is, therefore, essential to complete their objectives, and this involves the study of biological samples from donor patients that have been recruited according to criteria previously established in the design of the clinical trial. Nevertheless, it is becoming very common that, in the solicitation of biological samples, purposes that are beyond the objectives of the stated therapeutic trial research are introduced, like the development of ill-explained exploratory studies or the use in unspecified future research. In the digital era, the sequencing of patients' DNA needs to be considered as a serious security matter, not only for the patients, but also for their relatives. Genetic information may be easily stored, even forever, in digital files. This engenders a permanent risk of being stolen or misused in many ways. Furthermore, re-identification of sample donors is technically feasible through their genetic data. For these reasons, genetic analysis of samples collected in clinical trials should be restricted to the accomplishment of their main objectives or well justified goals.