u201c genes u201d formed from the used types of call sessions and the respective weights in brackets the last portion comprises u201c genes u201d reflecting the called area codes and the respective weights in brackets detectors generation block 116 in example 2 is performed just from the whole genes values there will be no manipulation like sub string or randomizing on the genes 39 values in yet a further example the usage records may comprise information reflected in tables shown in fig4 a and 4b concerning cases where one or more clients in the past performed a specific known type of fraudulent behavior in the system for example with respect to a login technique for further use of ip services however other combinations of genes are possible even such similar to those typical for the fingerprinting technique using such information the system is able to build a data string called a fraud dna to detect any attempt of using the system according to such a fraud again also in this case there will be necessary to select detectors of such a fraud characteristic string the technology of building a fraud dna and selecting detectors for that though being similar to the part of fingerprinting technique described in the examples 1 and 2 slightly differs from that in obtaining the characterizing genes suppose we have received from an expert several parameters that for his her opinion characterize a type of fraud which is typical for.