Method for protection against undesirable telemarketing advertisements (spam), a) whereby a first and second list (L1, L2) of identifications (id,rn) are established, with which a telemarketing advertisement or no undesirable telemarketing advertisement (spam) is expected, b) whereby the identification (id, rn) of the caller of an incoming call (call) is compared to the identifications (id, rn) in the lists (L1, L2), c) whereby a call (call) of which the identification (id, rn) of the caller is not found in the lists (L1,L2) is routed to a call processing (CALL-C), d) whereby, with the help of the call processing (CALL-C), a check is made on whether, with this call, telemarketing advertising (spam) is being received, e) whereby, as a function of the check result, the lists (L1,L2) are updated accordingly in such a way that the identification (id, rn) of the incoming call (call) is entered on either the first or second (L1, L2), f) whereby the calls (call) of which the identification (id, rn) of the caller is recorded in the second list are routed to the called party, and g) the calls (call) of which the identification (id, rn) of the caller is recorded in the second list are rejected, h) whereby a call (call) without identification (id, rn) is routed to th call processing (CALL-C), i) whereby, as a function of the investigation result, the call (call) is routed to the caller or rejected, characterised in that j) a call (call) with telemarketing advertising (spam) which, despite investigation in the call processing (CALL-C) is routed to the called party and is routed by the called party either to call processing (CALL-C) and signal samples or speech samples from this call (call) are acquired and stored in the call processing (CALL-C), such that these samples can be drawn on in the framework of the investigation of further calls (call) for comparison with the speech samples contained therein, in order, as a function of the comparison result, a further call (call) can be determined as being a call (call) with or without telemarketing advertising, or the called party, by an input at a terminal of the called party, arranges for the identification (id, rn) of the caller to be recorded in the first list. a) whereby a first and second list (L1, L2) of identifications (id,rn) are established, with which a telemarketing advertisement or no undesirable telemarketing advertisement (spam) is expected, b) whereby the identification (id, rn) of the caller of an incoming call (call) is compared to the identifications (id, rn) in the lists (L1, L2), c) whereby a call (call) of which the identification (id, rn) of the caller is not found in the lists (L1,L2) is routed to a call processing (CALL-C), d) whereby, with the help of the call processing (CALL-C), a check is made on whether, with this call, telemarketing advertising (spam) is being received, e) whereby, as a function of the check result, the lists (L1,L2) are updated accordingly in such a way that the identification (id, rn) of the incoming call (call) is entered on either the first or second (L1, L2), f) whereby the calls (call) of which the identification (id, rn) of the caller is recorded in the second list are routed to the called party, and g) the calls (call) of which the identification (id, rn) of the caller is recorded in the second list are rejected, h) whereby a call (call) without identification (id, rn) is routed to th call processing (CALL-C), i) whereby, as a function of the investigation result, the call (call) is routed to the caller or rejected, characterised in that j) a call (call) with telemarketing advertising (spam) which, despite investigation in the call processing (CALL-C) is routed to the called party and is routed by the called party either to call processing (CALL-C) and signal samples or speech samples from this call (call) are acquired and stored in the call processing (CALL-C), such that these samples can be drawn on in the framework of the investigation of further calls (call) for comparison with the speech samples contained therein, in order, as a function of the comparison result, a further call (call) can be determined as being a call (call) with or without telemarketing advertising, or the called party, by an input at a terminal of the called party, arranges for the identification (id, rn) of the caller to be recorded in the first list.