able to flush non sasl bucket via Rest without authentification, couchbase-cli doesn't allow it

not sure, that we should allow to flush non sasl buckets without authentification. Alk, this feature is correct?
then couchbase-cli also should allow

[root@cen-0422 testrunner]# curl -X POST -I http://10.3.4.144:8091/pools/default/buckets/default/controller/doFlush
HTTP/1.1 200 OK
Server: Couchbase Server
Pragma: no-cache
Date: Mon, 07 Jul 2014 10:46:28 GMT
Content-Length: 0
Cache-Control: no-cache

./couchbase-cli bucket-flush -c localhost:8091 --bucket=default
ERROR: Username cannot be empty. Please use -u or set environment variable CB_REST_USERNAME.