Webopi is a way to add and read reviews of any website: An item in an online shop, CNN's article, hosting company offer... and it doesn't matter whether a possibility of leaving a review is or is not given by the owners of those websites.
When the application is running, it's watching Firefox and Internet Explorer windows, and every time you visit a website Webopi displays reviews of this website as well as enables you to add your own opinion.
The opinions are stored in a central database, not related in any way to the owners of those websites, and so, they are under no control of the owners. You can use the "Active" checkbox to turn on/off Webopi activity.