Considering the game only lets admins see each player's brickcount, this would require both a client and a server sided mod.
EDIT: He's saying it's impossible.
It's possible, but the client wont see the brick counts unless the server has the mod, and if the server has the mod, not all the clients will see the brick counts.
EDIT: you're an idiot.
EDIT: It's impossible to get every brick from the server clientside only and then categorize them.
Wouldn't be too useful then, you can just type /brickcount