The use of metal detecting devices by the general public and the resultant plundering of archaeological sites is still one of the most painful issues in Czech archaeology. No simple or satisfactory solutions have been found. The aim of this paper is to objectively summarise the last 25 years of unrestricted use of metal detectors in the Czech Republic and its impact on the archaeological component of cultural heritage and on archaeology itself. The paper presents a quantitative model of metal detecting activities sourced from the available data. The results are employed to illustrate the effect of metal detecting activities on archaeological knowledge and to outline some related theoretical and methodological questions., Aleš Navrátil., and Obsahuje seznam literatury