Ledger.ACLOk() should return false by default

[xyzj]

my acl rules :

user01:
acl:
down/+/user01/#: 1
up/+/user01/#: 2

I want user01 to only be able to send messages with topic like 'up/json/user01/abc', 'up/base64/user01/def', but infact, user01 can send any topic, even does not start with 'up'.
So I think Ledger.ACLOk() should return false by default, just like Ledger.AuthOK()