[filtered FROM Bellatrix, Crouch and Caedus- no giving them ideas!]
Yeah, they'd be useful alright. We should definitely do what we can to deal with all of them before they figure this out, too. They're evil, not idiots.
A lightsaber is the weapon used by the Jedi and, by proxy, the Sith as well. It's a blade of pure energy and is defined by the person using it. Usually the Jedi build their own, able to choose their own color (typically blue or green). A Sith almost always has a red colored one. In my galaxy, it's a sign that you're a Force user and trained to be one. We use them for ceremony as well as in combat.
Ah. Well, hopefully you won't turn too grey, then. We wouldn't want you to look tired all the time when you aren't. That's not very distinguished at all.