You have to scan for planets, but a list of ships to attack gets handed to you on a platter.. But you don't know where they are either.
Why not make ships the same as planets?
Have to scan to find them.. no guarantee you'll find a ship.
And they obviously won't stay on your list very long unless you actively hunt them?
It would also encourage pvp's keep scanning equipment active.. and pay for its upkeep..
Only downside to this if you scan a ship that's protecting a planet.. would that give the planet location away? (picked up the ships radio chatter.. doesn't mean its around a planet.. but if you go and attack that ship, then the planet should be seen?)
There would also be a big incentive to ally with someone who has you on their scan.. heh.. depends on how long it lasts.
Leads me to a question, can people in the same legion attack each other?

Interesting idea, but I'm not sure how it would work within the scope of the game. It can be hard to find good targets as it is. If we had to scan ships, I have a feeling that it would devolve into higher level players with weak scanners just picking on low level players with weak cloak.

To answer your question - No, people can't attack others in their own legion.

Seems to me that you have made quite a number of posts regarding increasing the uses of sensors.
Finding a ship doesn't pinpoint the planet the ship is guarding. If that is true, anyone in the Kills leaderboard will not be able to guard any planet safely.
Scanning equipment are BIG. So if you need it to find targets, it would make the attacker very weak as they need to waste 50% or more decks to just find the ship. The current battle window system is fine. Not enough scan = cannot find someone cloaked.