Ok, these buttons are showing up everywhere now, from facebook to newspaper articles. Some might find them annoying, but I think they save a lot of time. Instead of having to quote something and add "this" or "well said" lalalala, this would be so much easier.
Additionally, if there was a dislike button, posts that were regarded as bad posts, trolling, etc, would get so many "dislikes" that the mods could probably see straight away which people to ban or warn etc. as on wowhead (I think?), if a post gets more than 5-6 dislikes, it is hidden, which makes the thread look a lot more tidy and without unnecessary comments about how bad or stupid people are, and without the "no you" kind of responses.
Any other ideas or comments on this? Maybe there is a better way that I haven't thought of.