In Athens a private initiative was required to bring a public suit against somebody. Lycur-gus considered the right of a voluntary prosecutor to take action on behalf of an injured person as one of the corner stones of the Athenian constitution (together with laws and courts). In some procedures in Attic law the successful prosecutors could obtain certain financial rewards: this practice favoured the birth of an anti-hero of Athenian justice - the sycophant, a professional informer and blackmailer. In Aristophanes' «Wealth» the Sycophant is one of the main characters; there are several hints and even evidence of the casual relationship between sycophancy and some institutional foundations of the Athenian society. The peak of professional blackmailing falls on the 4th century. The brief list of sycophantic activity is as follows: they blackmail the rich to settle out-of-court for a sum of money; they initiate the special prosecutions for reward; they bring «ordered» suits for money. The victim of a sycophantic prosecution could be anyone: a quietist (шфоуцхоу), a professional politician and especially the rich. Some professional informers are named in the article: Ago-ratus, Callimachus, Theocrines, Aristogeiton. The Athenian democracy was unable to solve the problem of sycophancy. To extirpate this evil it would be necessary to change the whole judicial system based on the volunteer prosecution. The sycophantic activity fell well into a pattern of socio-political relations: in such a way the demos maintained its power over the elite which was terrified of informers. From the psychological point of view it was meant to reveal the ill-feelings and envy towards the high and mighty. For a long time it was generally agreed that the sycophant was the one who abused the rights of о poD^ouevo*;. There is a new tendency in the modern scholarship: to protect sycophants from their critics and to stress the positive role of sycophantic prosecutions in the proper functioning of the Athenian democracy (A. Adkins, M. Christ, R. Osborne). The polemics with this opinion concludes the article.