Who is voting down the posts?

I've already commented in a particular thread but I'm raising this as a general question - has anyone else noticed recently that there are certain posts that, whilst they may hold unpopular opinions, are not in any other way derrogatory and yet they appear to have been arbitrarily voted down? Am I jumping at shadows here? Is there a little self-appointed censorship gang out there? In my opinion, someone or someones are flaunting the spirit of the website and censoring posts they happen to disagree with. If you're not a little more careful I will vote up at my discretion that which you've voted down. Whilst I hate the trolls I believe we should be seen to be democracy in action and my fear is someone is trying the autocratic approach. I have no trouble with voting down posts which villify, mock, or are just plain offensive but what I'm seeing goes beyond that. It makes me angry.....you wouldn't like me when I'm angry (sorry, couldn't resist the last bit). Anyone care to 'fess up?