What happens to the drk network when some masternode servers get hacked? If anyone can run them, do we all just trust that the individual's pc's have adequate protection??
I think DDOS attacks on the masternodes will be a big issue.
Absolutely! The network relies on masternodes being safe, secure, and online. When these get hacked the dark network could be in lots of trouble

The implementation is fault resistant. If one goes down, it will be quickly discovered and removed from the list and the rest will remain active.