diff --git a/core/aimedb.py b/core/aimedb.py
index 944153b..6d5bd57 100644
--- a/core/aimedb.py
+++ b/core/aimedb.py
@@ -177,6 +177,7 @@ class AimedbServlette():
     async def handle_lookup(self, data: bytes, resp_code: int) -> ADBBaseResponse:
         req = ADBLookupRequest(data)
         if req.access_code == "00000000000000000000":
+            self.logger.warn(f"All-zero access code from {req.head.keychip_id}")
             ret = ADBLookupResponse.from_req(req.head, -1)
             ret.head.status = ADBStatus.BAN_SYS
             return ret
@@ -207,6 +208,7 @@ class AimedbServlette():
     async def handle_lookup_ex(self, data: bytes, resp_code: int) -> ADBBaseResponse:
         req = ADBLookupRequest(data)
         if req.access_code == "00000000000000000000":
+            self.logger.warn(f"All-zero access code from {req.head.keychip_id}")
             ret = ADBLookupExResponse.from_req(req.head, -1)
             ret.head.status = ADBStatus.BAN_SYS
             return ret
@@ -252,6 +254,7 @@ class AimedbServlette():
         req = ADBFelicaLookupRequest(data)
         idm = req.idm.zfill(16)
         if idm == "0000000000000000":
+            self.logger.warn(f"All-zero IDm from {req.head.keychip_id}")
             ret = ADBFelicaLookupResponse.from_req(req.head, "00000000000000000000")
             ret.head.status = ADBStatus.BAN_SYS
             return ret
@@ -280,6 +283,7 @@ class AimedbServlette():
         idm = req.idm.zfill(16)
         
         if idm == "0000000000000000":
+            self.logger.warn(f"All-zero IDm from {req.head.keychip_id}")
             ret = ADBFelicaLookupResponse.from_req(req.head, "00000000000000000000")
             ret.head.status = ADBStatus.BAN_SYS
             return ret
@@ -319,6 +323,7 @@ class AimedbServlette():
         idm = req.idm.zfill(16)
         
         if idm == "0000000000000000":
+            self.logger.warn(f"All-zero IDm from {req.head.keychip_id}")
             ret = ADBFelicaLookupExResponse.from_req(req.head, -1, "00000000000000000000")
             ret.head.status = ADBStatus.BAN_SYS
             return ret
@@ -377,6 +382,7 @@ class AimedbServlette():
         user_id = -1
         
         if req.access_code == "00000000000000000000":
+            self.logger.warn(f"All-zero access code from {req.head.keychip_id}")
             ret = ADBLookupResponse.from_req(req.head, -1)
             ret.head.status = ADBStatus.BAN_SYS
             return ret