Disclosed are various embodiments for facilitating the anonymization of unique entity information when transmitting data to services. A content server may store entity identifiers that respectively represent entities associated with the content server. The content server may send anonymized responses to requests for data from multiple services, the data being associated with entity identifiers. The anonymized responses may comprise the data requested in association with anonymous entity identifiers as opposed to the entity identifiers. The requesting services may each receive a different anonymous identifier representing a single entity.