I was looking at a post that had been liked, and I clicked on it, to see who had liked it. When I hovered my cursor over their name, a red cross appeared to the left that gave me the option to delete the rating. So, I've gone back to a post of mine that someone else had liked. I then clicked the "delete rating" button, it did delete the rating and when I checked my profile page afterwards, I had one less like than I had had before. I'm calling it a bug because I can't see why I (and, I presume, other non-moderator people) should be able to delete ratings that were left by others. If it's intentional then I have to wonder why that's the case.