Not necessarily. There’s nothing illegal about contacting criminals if you have no intention of committing a crime. The FBI might in good faith be looking for witnesses to come forward and be available to testify in a criminal case against the administrators.
It’s actually entirely reasonable for regular people to contact botnet administrators without any intention of purchasing criminal services. Security researchers sometimes do this when investigating the source of botnet attacks or when tracing machines they deliberately allowed to be infected (honeypots). The FBI may be very interested in getting testimony from these security researchers, even outside the scope of expert witnesses they may select out of the researchers they’re regularly in contact with.
It’s actually entirely reasonable for regular people to contact botnet administrators without any intention of purchasing criminal services. Security researchers sometimes do this when investigating the source of botnet attacks or when tracing machines they deliberately allowed to be infected (honeypots). The FBI may be very interested in getting testimony from these security researchers, even outside the scope of expert witnesses they may select out of the researchers they’re regularly in contact with.