$ curl -H "User-Agent: User-Agent: Mozilla/5" -kvs 'http://www.microsoft.com'
* Trying 118.123.102.107...
* TCP_NODELAY set
* Connected to www.microsoft.com (118.123.102.107) port 80 (#0)
> GET / HTTP/1.1
> Host: www.microsoft.com
> Accept: */*
> User-Agent: User-Agent: Mozilla/5
>
< HTTP/1.1 403 ……