Can Samsung Smart TV's be hacked? Is there protection for these TV's

That would depend on what platform is running on the smart TVs.  If it's an Android based platform then it might be possible for us to get the Android version working on them.  Depends how much they have the platform locked down.
 
I haven't heard of any TVs getting hacked yet, but I'm sure it will happen at some point.

I have not heard of Samsung TV's being hacked but these 2 articles maybe of interest to you:
Hey, does your Smart TV have a mic? Enjoy your surveillance, bro
Philips Smart TVs riddled with security and privacy flaws, researcher reveals

I have seen some information on hacking Samsung TVs but they are based on old firmwares that have been patched.
 
As Smart TVs and other connected devices in The Internet Of Things move towards more open systems like Android there may come a point that security apps are available for them, but for now the need simply is not there. 
 
-Dan
 
 
 

Hi Again @ I have just posted an article in the Security News you maybe interested in related Samsung Smart TV.s
 
Samsung SmartTV models transmit voice, and more, to a third-party service
The part starting "Under the Voice Recognition section of the policy is reported:"  will be of particular interest.