Eliciting requirements is an important issue of system development projects. Some approaches propose to identify requirements by analysing system malfunctioning. Different sources of malfunctioning are dealt with by these approaches: obstacles, conflicts, risks, etc. Our proposal is to analyse each of these sources of malfunctioning using a single notion that we call "threat". We propose to use this notion in a method that guides the identijication and analysing of each of these sources of malfunctioning. The method helps eliciting requirements toprevent the threat. A threat is defined by a number of variables. This paper presents a literature review of all threats that relate to users. The review is based on a framework that includes several perspectives to analyse user error. The user threats is part of a global threats classification that also covers hardware, environment, design and project types of threats.