Actually the system is very complicated. There's a whole list of criteria for how much rep-giving power a member has, based on how long you've been a member, how many posts you have, how much rep you have, and more.
awhig is right about the admin's rep-giving power, but senior members, believe it or not, are not necessarily limited to that. So it's theoretically possible for someone to be able to give more than ten points, although I don't know whether it's the case right now.
Complicated, huh?
