Thank you for your review. I know what you say, there are some things which can improve the addon, but as an excuse, all I can say is that I first created this addon for me only, to know which seller should I avoid in the future. Then, I thinked that it could help not only me, but many other people and in this way, I can know more bad sellers too. After that, I have beautify the first tryout ot the addon and published to everyone.

It will have more features in the future, I just need to spend more time with MDN programming, it has some different functions from the pure javascript.

Adding bad sellers to the database addon, it will require always a person to check the truth from the evidence... So, with sending e-mail or filling some standard forms, it will result the same action for checking the evidence. But, as I said, the plugin will grow bigger in time.