http://freedns.afraid.org/faq/#14
1). Public - If you add your domain as
public, this shared queue will not be
used at all, others will be permitted
to attach to subdomains off your
domain without involving your
approval.
2). Private - If you add your domain
as private, then you will be able to
screen your domains of which you
decide to allow and deny. While
domains are in the shared queue
pending acceptance or not, they WILL
function on the global Internet. It is
assumed that you will support this
concept, and approve the majority, and
only deny those that you deem
offensive or slanderous.
3). Invisible / Stealth - If you add
your domain as invisible (premium
members only), your domain will not be
available for anyone else but you to
use, and the shared queue will not be
used at all. Invisible gives you
completely private domain hosting
where no one else may attach to your
domain. Also some domains go in
invisible by default if they come from
other free DNS providers and the like,
then they are not shared. If you
believe your domain is being
incorrectly marked as invisible and
wish to share it, contact me.
If you don't want to share your domain then you can either:
- Host your own dns
- Pay for DNS services
- Move your domain to a registrar that offers DNS for free
Your DNS isn't "hijacked", you signed up for a free service that involved sharing subdomains of your domain.