Data monitoring by citizen scientists in the field of biodiversity is mainly achieved for free, since it is primarily carried out by amateurs who are not paid for what they report. This lack of remuneration has been claimed to be either exploitative by those who study inequality of access in amateur circles, or empowering by those who promote new digital solutions for naturalist reporting. In this context, Faune France, a major citizen fauna database in France, represents a renewed relationship between scientists and the general public contributing to this digital initiative. In contrast to explanations in terms of personal motivation or social stratification, participation in Faune France reveals a special attachment to the object-birds, butterflies, frogsand the obligation toward nature felt by contributors, shown by their desire to share their observations digitally to recipients for the most part unknown. Rather than a means of 'luring' amateurs when they give away information, commitments such as Faune France reporting are based on attachments to nature and others, and cautious information disclosure. Data are given to an indeterminate other, be it distant scientists or other participants on the internet. Hence the stress on data sensitivity, and on responsibility in the description of naturalists' contributions.