I see people now appending #sportstalk #actnearn and #palnet to every one of their posts regardless of topic. If the token earnings are linked to tags, what's to stop people from just adding the #sportstalk tag to unrelated posts?
My guess is the same thing stopping unrelated posting in subreddits: downvoting.
Perhaps effective curation. At it is stage, many experiment to learn stuff. not every case is spam.