An Electronic Article Surveillance (“EAS”) system is provided wherein the system is configured to detect passive radio frequency identification (“RFID”) tags. The system can be configured to read the passive RFID tags and produce a corresponding emulated EAS signal to initiate an alarm on a detected tag. The system can transmit the emulated EAS signal to a legacy EAS system thereby utilizing an existing EAS infrastructure. In some embodiments, a composite EAS system is configured to detect RFID tags and other EAS tags, wherein the composite EAS system comprises a legacy EAS system and an RFID-based EAS system configured to produce an emulated EAS signal.