They appear in systems with wars or lockdowns.
They don't really do anything unless you have a mission to kill security then its an easy place to do it.
Doesn't killing the Naval vessels there cause "damage" to the owning factions influence and increase lockdown et cetera?
Yes, so if you are part of the opposition then you can kill them.
Didn't want to start a new post about checkpoints. If checkpoints are what they say above, shouldn't you warp into the system at them instead of the sun? Just a thought.