Found this article today that fits the profile of a few vociferous members - I am not voicing an opinion but its what many have said, the vocal minority can can often really believe what they are saying is the truth.
Stanford Study Explains Internet Trolls
In a study conducted at Stanford, psychologists discovered that people who hold extreme opinions are more likely to voice them loudly than those who hold moderate opinions. At last, science has explained most of what you read on the internet.
Ohio State professor Kimberly Rios Morrison polled Stanford University students about what they thought about students drinking alcohol. What she discovered was that the students with the most extreme pro-alcohol stance expressed their opinions most readily, in general because they believed that they were voicing the majority opinion. But polls showed that the majority of students had a moderate to anti-alcohol stance. When pro-alcohol students were shown evidence that most people didn't support their views, they were far more reluctant to express their extreme opinions.
Said Morrison:
It is only when they have this sense that they are in the majority that extremely pro-alcohol students are more willing to express their views on the issue.
Sounds like this study explains internet trolling and flame wars too. People with extreme views who are extremely loud about them manage to delude themselves into thinking everybody agrees. Morrison added:
You have a cycle that feeds on itself: the more you hear these extremists expressing their opinions, the more you are going to believe that those extreme beliefs are normal for your community.
No word yet on how to break the cycle. But we can only hope further research will lead to a simple way to cure extremists of their belief that everybody shares their opinions and wants them to keep talking.