Karma Blocking

The act of not upvoting for an arbitrary reason and declaring it to the world. Typically results in no praise and the karma blocker looking like an asshole.

Jack: "I would upvote, but the counter is already at 69, hahaha"
Bob: "Hey man, stop Karma Blocking and just give them their upvote"

karma block

A redditor who has not been successful with his last posts and seeks to downvote every possible upload. They:
-Point out reposts
-Correct Grammar
-Downvote a user's past uploads

I started out strong on reddit with a solid 30 upvotes on my post, but that karma block pointed out that it was a repost :/.