The way I've always understood REST, it's all about having a rich vocabulary of nouns (resources), but a very limited vocabulary of verbs (basically only Create, Read, Update, Delete). So, in a RESTful version of this site, you don't 'upvote' a post (by which I mean call a remote procedure called 'upvote' with the post ID as an argument), you instead 'create an upvote' related to the post.