Techniques for detecting spam accounts in a system are described. The system may analyze speech characteristics of communication content (e.g., telephone call content, VoIP content, audio messaging, etc.) to determine whether multiple devices or user profiles are associated with overlapping communications. The system may also analyze text transcriptions of communication content to determine whether multiple devices or user profiles are associated with overlapping communications. If so, the system may mitigate, such as throttling service, disabling accounts, and the like.