Dear Prof. Menczer, I received from the Dean of the Faculty of Engineering copy of your letter dated October, 30 2007. I'm writing to apologize to you in the most sincere way for what happened; at the same time, please, believe me when I say that really I was induced in error because of the excessive trust I had in Mr Gatani, whom I esteemed greatly. I would like to report some facts in the following, if only to make the circumstances that generated my huge assessment error clearer to you. Mr Gatani got his laurea degree with a dissertation on multicast routing that I tutored with Prof. Gaglio; this work later produced some publications, including one that appeared on the Parallel Computing journal. His brilliant academic career was recognized by the Dean of the faculty with a special mention, also considering the fact that his final mark was calculated starting from a basis of 118/110. After Mr Gatani joined the Ph.D. course, Prof. Gaglio kindly agreed to serve as his official tutor since I was not part of the Ph.D. Board yet. In that occasion, the student was to choose the topic for his research and he was given the opportunity to choose any topic in the field of networking, he deemed more suited for his aptitudes. His choice fell upon unstructured P2P systems. While I closely tutored him during the works related to the topic of his laurea degree, he was given much more freedom for his Ph.D. research activity, although I still frequently discussed with him about the ideas he proposed. In fall 2004 he worked toward the submission of a first series of papers. In this period he also tutored several laurea theses related to his research topic, that produced a lot of code used for his simulations. No relevant accidents happened until we received Prof. Shen's first e-mail. Upon request for an explanation by Prof. Gaglio and myself, Mr Gatani provided only a partial justification, not mentioning any other previous original source, and simply admitting the verbatim copy of some sentences from your WWW'04 paper and the reproduction of some figures to illustrate his own results. He also claimed that your paper was just one among many sources he had examined during the preparation of his work, and that the basic ideas of the work were original. That is why I asked him to reply to Prof. Shen on behalf of all authors in order to apologize and make amends for the incident. The following e-mail by Prof. Shen, pointing out the presence of the same issue on some other works of ours, induced me to write my only reply; with hindsight, I understand that this may have been misunderstood, especially in the light of a complete factual knowledge, that I was unfortunately still lacking at that point. In this occasion, Mr Gatani did show us your IASTED WTAS'05 paper, but several factors (such as, the not too detailed description of the algorithm in that paper, the lack of any pseudo-code or descriptive figures, our complete trust in our young co-author, his documented experimental activities, and finally the fact that this paper is chronologically successive to our first published work) led Prof. Gaglio and myself to believe we were in the presence of a similarity in the proposed approaches, rather than serious plagiarism. Only now it appears clear to me that my total trusting in my young pupil led me to a fallacious assessment of the situation. From that moment on, however, believing that our two groups were carrying on similar research activities, I took great care in having any similarity stressed in all of our successive publications. Getting to know about your letter dated October 30 07 took me as a surprise. After a lengthy and thorough investigation on my part, eventually finding your unpublished work "http://www.informatics.indiana.edu/research/publications/6S.pdf" allowed me to understand my huge error. I also hope you will understand how an unpublished work may have escaped our earlier check. I admit I failed in conducting a more accurate investigation last year, and I want to give you my most sincere apologies once again. I should rather have promptly interrupted any publication activity in that field last year. With hindsight I realize how the facts may have appeared to you and your co-authors. It would have been really inconsiderate and unwise on my part if, knowing the actual plagiarism source, I had kept on producing publications that would result in an obvious damage for my reputation and for the reputation of other colleagues with whom we had began collaborating. Lacking important information details may have generated this incomprehension. In the light of the recent evidence, I am immediately taking all the necessary actions in order to have all the papers published on the topic withdrawn as soon as possible. In the following, a list of the papers involved. I hope that these actions on my part, although belated, may serve as partial repair for any damage this event may have caused to you, your co-authors, and also the colleagues of mine that have been involuntarily involved. I would be glad to have a chance to explain to you in person and in deeper details the facts that I described here; I am truly and deeply sorry for any damage this regrettable event may have caused. Sincerely Giuseppe Lo Re List of the published papers 1. Luca Gatani, Giuseppe Lo Re and Salvatore Gaglio. An Adaptive Routing Mechanism for Efficient Resource Discovery in Unstructured P2P Networks. Proc. International Conference on Computational Science and Its Applications (ICCSA 2005), Part III. Lecture Notes in Computer Science vol 3482/2005, p. 39-48. Springer. ISSN 0302-9743 (Print) 1611-3349 (Online) 2. Luca Gatani, Giuseppe Lo Re, Alfonso Urso and Salvatore Gaglio. Reinforcement Learning for P2P Searching. Proc. 7th International Workshop on Computer Architecture for Machine Perception (CAMP'05), pp. 303-308. ISBN: 0-7695-2255-6 3. Luca Gatani, Giuseppe Lo Re and Salvatore Gaglio, An Adaptive Routing Protocol for Ad Hoc Peer-to-Peer Networks. Proc. 6th IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks (WoWMoM'05), pp. 44-50. ISBN: 0-7695-2342-0 4. Luca Gatani, Giuseppe Lo Re and Salvatore Gaglio. An adaptive routing mechanism for P2P resource discovery. Proc. 5th IEEE International Symposium on Cluster Computing and the Grid (CCGrid'05), Volume 1, pp. 205-212. ISBN:0-7803-9074-1 5. Luca Gatani, Giuseppe Lo Re and L. Noto. Efficient Query Routing in Peer-to-Peer Networks. Proc. 3rd IEEE International Conference on Information Technology: Research and Education (ITRE'05), June 27-30, 2005, Hsinchu, Taiwan, pp. 393-397. ISBN: 0-7803-8932-8 6. Luca Gatani, Giuseppe Lo Re. An Efficient Adaptive Strategy for Searching in Peer-to-Peer Networks. Multiagent and Grid Systems 1 (3): 209-224, 2005. IOS Press, Amsterdam. ISSN:1574-1702 7. E. Ardizzone, L. Gatani, M. La Cascia, G. Lo Re, and M. Ortolani. Enhanced P2P Services Providing Multimedia Content. Proc. of the Eight IEEE International Symposium on Multimedia, 2006. ISM'06. pp. 637-646 ISBN: 0-7695-2746-9 8. E. Ardizzone, L. Gatani, M. La Cascia, G. Lo Re, and M. Ortolani. Enhanced P2P Services Providing Multimedia Content. Advances in Multimedia, vol. 2007, Article ID 26070, 12 pages, 2007. 9. E. Ardizzone, L. Gatani, M. La Cascia, G. Lo Re, and M. Ortolani. A P2P Architecture for Multimedia Content Retrieval. In LNCS Advances in Multimedia Modeling Volume 4351/2006 pp. 462-474 ISBN 978-3-540-69421-2 10. E. Ardizzone, L. Gatani, M. La Cascia, G. Lo Re, and M. Ortolani. Distributed Multimedia Digital Libraries on Peer-to-Peer Networks. In: Proc of The 14th Intl Conference on Image Analysis and Processing. 2007. (pp. 77-82). 11. Luca Gatani, Alessandra De Paola, Giuseppe Lo Re, and Salvatore Gaglio. An Adaptive Routing Mechanism for P2P Resource Discovery. In Journal of Grid Computing. Springer Netherlands. ISSN 1570-7873 (Print) 1572-9814 (Online). -- Giuseppe Lo Re, Professore Associato Dipartimento Ingegneria Informatica Universita' di Palermo V.le delle Scienze, Edificio 6 90128, Palermo - ITALY