I'm sure if you've participated in reddit discussions/arguments that you've experienced cowardly, pointless or brigading downvotes
If the comment truly needs a downvote then I don't see why the user downvoting should care if they're anonymous or not.
If this were to be implemented, simply clicking over this section of the comment http://i.imgur.com/CUjrhiH.png would bring up a scrollable list of users
I would like to see what you think about this and any negatives that this could bring.
EDIT: When I say sitewide, this of course wouldn't include the anonymous subverses.