Suggesting to add upvote/downvote icons to the comments.
Than author of well upvoted comment can be rewarded with points.
I don't like this idea; comments are intended to do the following:
Users already get rewards for having upvoted comments, specifically the Commentator and Pundit badges, why would they need reputation as well?
If there is something wrong with a comment, it can be flagged for moderator attention.
Random downvotes on questions and answers are annoying enough, I don't want to get randomly downvoted on comments now as well.