Did you get the X10 controlled power supplies for them?
Technically each one could have had a receiver or one receiver could have been used. More than one would need each on a different channel and could still interfere with each other sometimes.
The cameras supply was X10 power line controlled. Using a Common X10 House Code and 4 Unit codes. 1-4,5-8,9-12 or 13-16.
If you sent a On command to one of the four in the group. The other three automatically turned Off with out being directly commanded Off. Like C1 On would automatically turn Off C2,C3 and C4. When first powered On. They defaulted to On. So until one was commanded On. They could step on each other.
The camera receivers where Composite Video and analog audio if that module included audio. So a Composite video input on a TV or Monitor would be need.