As of current we have defense stations which are pretty useful for defense... But I feel we need another tool we could buy to help protect systems without changing the balance in the game too drastically..

what I propose: just like a ds, thus family defense fund can now also be used to buy blackouts for systems.. these are much cheaper than ds.. their basic function is to cause the system to dispplay no information about that system..
E.g you blackout a system.. a guy not in your fam clicks the system to attack.. all that showses up is the planet's with no information underneath them... doesn't show who owns them or by what fam..
on top of this if you "find targets planets" a guy whos got planets under protection from this device it will bring a list up below his planet list from the op saying "23 planets protected by gravitational interference we could not get these coordinates" or smt like this...
The only thing a blackout would require would be one planet on the map.. when you own aplanet you can build one.. but if another family gets just one planet he can see the full system but only his family can...
The device only breaks if the family who built it loses all planets in. System...
However it will display whether the planet is owned or empty..

it's a great way for families to defend their planets and slows down an attacker's ability to just pwn in one go...