chilling effects need to be kept in perspective; for example, while I'm completely fearless about telling off the govt whenever I wish, no way I'm going to reveal how I feel about Snowden to the HN community: I'd be ostracized!
Please consider sharing!
Not that it matters, ostracization means losing a few HN epeen points, so meh :)
(In the interest of keeping topicality, one could argue the above are examples of chilling effects in a community)
people who care to take part and comment here might be more sensitive to social approval than the median - the quest for approval might ba a motive to participate. Therefore the loss of a few points might be more of a loss for them. In the long run that is not so good for the diversity of opinions, but so it goes...