Somebody wrote some down vote bots earlier, just to downvote everything... I think a couple of them got banned, but maybe they put them back up....

I believe a lot of the down vote behavior is the classic " I disagree ". Though I wish people used downvotes more sparingly, and to indicate they think somebody is not contributing at all to the conversation.

I do think the down votes have a chilling effect on some people, especially people who like to lurk, they see a bunch of downloads on a conversation they're unlikely to say anything.