It is my understanding that all HOA's are public while the broadcast is active. Once you close the on air hangout you can go to YouTube and change the privacy settings. I hope there is an enhancement on the way that will allow one to limit who sees the live broadcast during the hangout.
I recently did an on air hangout with someone so that a five year old could share their birthday gifts. It was really cute and I had used the on air feature so capture the session so that it could be shared with other family members.
All was fine until I received messages from a couple of folks I did not know who enjoyed the on air hangout.
I sure hope that in the future I will be able to limit who sees the live broadcast to either those I invite or those with the link. Either way I would have some control.
I love the concept, I just think it needs a little more security.
Thanks Google for continuing to amaze me with your new offerings.