The plus one button was Google’s answer for the Like button from Facebook. News reports say that the plus one button has started showing up all over the web and is doing really well. So, what about a “Minus One” button ?
When I saw the minus button, I emailed it’s developer Julien and asked what does it actually do. Because, officially, there is no minus option, or dislike option. You can minus your plus, only if you have already liked something.
Here is the response I got.
You can add -1 on any post in your stream or people public stream even if you did not +1 on the post. It is independent. Only people who have already installed the addon can see the -1 of the others -1′s users
Get the idea ? I am not sure if Google will ever have a minus one option officially, until then, this is something that can satisfy your need for expressing dislike on the web, provided, you get to meet few people who are already using it.