Highly unnecessary, while it's on a good note, I've never been KS'd summoning. I just use a good, small, obscure map that no one goes to. At all.
If it's ever been found, well, unless they're just PvP players wanting to be a douche, I can pretty much kill any MVP-er.
If you want some more security, every time you summon a monster take a screenshot to prove that you did, in case of kill theft. Use this in your defense: