well as on the legal assessment of anti-SPIT measures and mechanisms. The deployment of anti-SPIT mechanisms raises a lot of issues relating to everyone's right to respect to his private life and his cor- respondence. The confidentiality of communications is guaranteed explicitly by several national, supranational and international legal instruments [among them: the Fourth Amendment (USA), the EU e-Privacy Directive (Art. 5), the European Convention for the Protection of Human Rights and Fundamen- tal Freedoms (Art. 8)]. Both the EU e-Privacy Directive and the European Convention for Human Rights prohibit any form of interception, e.g., a third party acquiring access to the content or traffic data (data processed for the conveyance of a communication or the billing thereof) to private communica- tions between two or more correspondents. Such interceptions are acceptable only on the basis of some fundamental criteria, i.e., legal basis, need for such a measure in a democratic society and conformity of the measures adopted with legitimate aims such as national security, public safety or the economic well-being of the country, prevention of disorder or crime, protection of health or morals, protection of the rights and freedoms of others. Electronic communications are combining, in the most regular cases, both the notions of "private life" and "correspondence" [5]. Interception, open- ing, reading, delaying reception of communications or impeding the sending of messages have been considered by the Courts to be an intrusion into the right of correspondence, which includes not only confidentiality but also the right to send and receive correspondence. In this institutional context anti- SPIT mechanisms have to respond to a double challenge: they have to prevent successfully the invasion into the receiver's privacy while respecting the pri- vacy and other fundamental rights of communicating parties, even of potential SPITters. Filtering and withholding of received communication constitutes an inter- ference with the fr