def lock(self):
        """Lock thread.

        Requires that the currently authenticated user has the modposts oauth
        scope or has user/password authentication as a mod of the subreddit.

        :returns: The json response from the server.

        """
        url = self.reddit_session.config['lock']
        data = {'id': self.fullname}
        return self.reddit_session.request_json(url, data=data)