I have been receiving anonymous comments in my blog and it can be quite frustrating to receive those spam comments. But I learned something that day that I can actually block anonymous comments. This is by going to your "settings" and click "comments" and under "comments", click on moderation. With moderation enabled, me as the blog owner is able to control what comments I want to appear in my blog by clicking on "publish", "delete" or "spam". I feel so much better after that.