I was looking through the items list and see that only one faction owns a certain type of item. Does that mean they are the sole owner of those DC's? Or can another faction own it as well?

I ask because the faction that owns the DC is not selling or producing to the public (their right to do so) , just wondering if another item faction was to be created, could it be given to that faction too?

No. You can not obtain "unique" DCs. The only DCs you get from creating a faction are listed on the Faction Creation rules page.

As the above said, with the added stipulation that this is subject to change once R&D is coded and released.

Best to wait until R&D which should unlock (eventually) all the entities for anyone wishing to spend the time researching them.

Will there be any way for factions to protect their restricted tech (Besides blowing up anybody who tries to research it)?

hope no one finds it on the tech tree?

Protection and prayer are mutually exclusive.

TO my knowledge there will be no form of protection.

A few years back there was discussion amongst the devs such that certain DCs would be limited to the first X people to get there, mainly for super stuff like the SSD etc. However I am unsure if that has changed since.

Maybe a kind of Patent Protection might be in order for R&D'd DCs, but TBH, I think balance-wise it's far fairer to just award an achievement or let the First people to get the pinnacle R&D suggest a custom Name for their form of the entity. Imagine an arms race between GE and GA, they both sink ludicrous amounts of Research Points into trying to get the highest tech, and because one beat the other by as little as 1 second, the other's research now means nothing?