  Semantic communication aims to facilitate purposeful information exchange
among diverse intelligent entities, including humans, machines, and organisms.
It emphasizes precise semantic transmission over data fidelity, striving for
meaningful expression while optimizing communication resources for efficient
information transfer. Nevertheless, extant semantic communication systems face
security, privacy, and trust challenges in integrating AI technologies for
intelligent communication applications. This paper presents a comprehensive
survey of security and privacy threats across various layers of semantic
communication systems and discusses state-of-the-art countermeasures within
both academic and industry contexts. Finally, we identify critical open issues
in this burgeoning field warranting further investigation.
