They're op, the lightning kills any players no matter where they are at. Making this game mode a lot less fun. For you that don't know, a missed frag = lightning. (Apparently) If you're remotely close to the frag grenade you will lose 4 - 6 hearts.
P.S. I understand the point of a frag grenade, where you can kill the campers... But it's so broken it's not even funny. Remove the lightning too.