The comments section of blogs critical of powerful public or private entities are regularly infiltrated by fake comments written by paid workers of those entities.
These paid commentators will attack the critical information in length comment after comment, drowning out those that disagree with the actions of the powerful entity.
As you might expect, China engages in this. People are paid to promote the official Chinese point of view around the internet. China, in case you have forgotten, is a non-democratic communist dictatorship.
Our US government is interested in this as well. Read this actual academic paper authored by a high government official that advocates flooding blog comments sections with pro-government material.
(There are many examples of big businesses doing this too - I will try to collect some examples for you soon)
My favorite example is when celebrities actually try to anonymously comment on critical articles on themselves! Scott Adams of Dilbert fame was busted doing this.
Here's a list of other famous/rich people concealing their identities in comments sections. Yes, it's a Wikipedia link, but they do include sources for these examples.
Solutions: 1. Stop Treating the Open Web as an authoritative source. 2. Learn to Think For Yourself, even when you perceive your own views to be unpopular.