diff --git a/demo.py b/demo.py
index e8a8a54..2d20ca8 100644
--- a/demo.py
+++ b/demo.py
@@ -57,6 +57,13 @@ async def main(args: argparse.Namespace):
 
     push_creds = apns.PushCredentials(
         CONFIG.get("push", {}).get("key", ""), CONFIG.get("push", {}).get("cert", ""), token)
+    
+    def register(conn, users):
+        import emulated.nac
+        vd = emulated.nac.generate_validation_data()
+        vd = b64encode(vd).decode()
+        users = ids.register(conn, users, vd, args.client_data)
+        return users
 
     async with apns.APNSConnection.start(push_creds) as conn:
         # Save the push credentials to the config
@@ -112,12 +119,7 @@ async def main(args: argparse.Namespace):
 
                 users.append(ids.IDSAppleUser.authenticate(conn, username, password))
 
-            import emulated.nac
-
-            vd = emulated.nac.generate_validation_data()
-            vd = b64encode(vd).decode()
-
-            users = ids.register(conn, users, vd)
+            users = register(conn, users)
 
             CONFIG["users"] = []
             for user in users:
@@ -134,10 +136,7 @@ async def main(args: argparse.Namespace):
 
         if args.reregister:
             print("Re-registering...")
-            import emulated.nac
-            vd = emulated.nac.generate_validation_data()
-            vd = b64encode(vd).decode()
-            users = ids.register(conn, users, vd)
+            users = register(conn, users)
 
 
         # You CANNOT turn around and re-register like this:
@@ -271,5 +270,6 @@ async def output_task(im: imessage.iMessageUser):
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument("--reregister", action="store_true", help="Force re-registration")
+    parser.add_argument("--client-data", action="store_true", help="Publish client data (only necessary for actually sending/receiving messages)")
     args = parser.parse_args()
     trio.run(main, args)
\ No newline at end of file
diff --git a/ids/__init__.py b/ids/__init__.py
index af8cab2..52a5fdb 100644
--- a/ids/__init__.py
+++ b/ids/__init__.py
@@ -106,7 +106,7 @@ DEFAULT_CLIENT_DATA = {
 
 import uuid
 
-def register(push_connection: apns.APNSConnection, users: list[IDSUser], validation_data: str):
+def register(push_connection: apns.APNSConnection, users: list[IDSUser], validation_data: str, publish_client_data: bool = True):
     signing_users = [(user.user_id, user.auth_keypair) for user in users]
 
     # Create new encryption identity for each user
@@ -125,7 +125,7 @@ def register(push_connection: apns.APNSConnection, users: list[IDSUser], validat
         else:
             special_data = DEFAULT_CLIENT_DATA
         user_payloads.append({
-            "client-data": special_data,
+            "client-data": special_data if publish_client_data else None,
             "tag": "SIM" if user.user_id.startswith("P:") else None,
             "uris": [{"uri": handle} for handle in user.handles],
             "user-id": user.user_id,