I have recently had dozens of comments in a row
moderated down after I participated in discussions about global warming, and replied to denialist comments. This has happened several times, so it seems that there is an organized effort to remove facts from the public eye, much like religious zealots have done throughout history.
I'm not just getting a couple of down-mods here and there, but each mail about moderation contains multiple down-mods in a row.
It's a bit like the organized efforts by the entertainment industry, companies like Microsoft, etc. in the past. Almost as if mod points are for sale.