An information provision exchange service system that can securely prevent the transmission of information that can be used to identify a user to another party and enable users to provide and exchange information between themselves free from confidentiality concerns. A server checks registered personal information to determine whether or not information that can be used to identify any of the users using a plurality of communication terminals is included in information exchanged between the communication terminals via a communication network, and replaces the information that can be used to identify a user with other information if the information that can be used to identify the user is detected in the information exchanged between the communication terminals via the communication network.