You can only see who has given you rep if they sign their name in the comment. Otherwise it isn't viewable to you through the user control panel. As for disabling it, you can't, that feature is disabled AFAIK, the FAQ isn't something we wrote, it is just the generic vB one.
Edit: I do disagree with people who give negative reputation because for example they think the OP should have used google. Similarly, posts in that vein will get you in trouble.