I read somewhere that downvotes are capped to -4 and it made me much less likely to self-censor when I felt like I had a valid point.
I know that the people who disagree with me outnumber those that agree, but the way that the upvotes bounce up and down tells me there are more people out there that agree with me than I would have assumed.
(Plus I think I've only made it down to -4 once or twice)