This doesn't rate media Bias, rates public transparency (shadyness) of the news source.

TLDR; Beware the negative 1-star reviews, this plugin is excellent.

I will first state, this plugin does what I hoped it would do. It gives me a nutrition label of how much or little to trust the source of information. In a world where press I labeled as "Fake News" and "the enemy of the people", it's not surprised that there are folks that are giving this plugin a 1-star rating because CNN doesn't have a dangerous-source label to it.

They appear to be fair with all political spectrums, Fox/CNN/MSNBC in the US are all treated as trustable sources. Obviously, there is going to be strong opinions when it comes to the opinion pieces. They address this in their media overview.

The authors behind this plugin are in a difficult situation, and everyone will have some news source they like that they believe it is trustable. In that case, I'm seeing a lot of the negative reviews shooting the messenger, which is the NewsGuard team.

I am very appreciative of the work that the team behind this plugin are doing. I hope they continue down the path of giving details information in the form of ownership, integrity, and intention of the news sources we trust and be able to vouch for news sources we're not familiar with and put the red-flag up when bad actors are in the mix.

If you find yourself hating the results of this plugin, maybe you should be re-thinking the sources of information you trust. The problem isn't the plugin! Facts are a fickle thing, and that's what the group behind this plugin appear to be doing a good job giving us. To see the truth, and to then get angry about it and give the plugin a 1-star rating is intellectually dishonest and unfair to the authors. Most likely, the person that gave the rating is a 1-star intellect that doesn't want to hear anything that contradicts their echo-chamber social network.

It's the best in news technology because it helps fight for the people against misinformation.

NewsGuard is great!

Amazing tool that assists in separating those who spread false propaganda and verifiable facts.

Great addon, even better for upsetting trumplings

This plugin is an excellent resource for determining the general reliability of a news source..
It should be noted though that the plugin does not claim, nor could it reasonably claim to verifiy any news source as 100% reliable.

One further observation, almost every negative review comes from someone who tried to use this to verify their pre-existing assumptions about a news source, and dismisses the validity of the plugin because it does not confirm their existing presumptions - curiously enough the very target audience most biased sources prefer, imagine that.