The brains are being skewed with the content making fears disproportionate to reality and raising anxiety which disables rational thought and constructive activity.
That's simultaneously too optimistic and too pessimistic. Optimistic because it assumes that someone, say, replying to a comment on Hacker News, is doing that instead of something incredibly constructive. Pessimistic because it also assumes that those negative emotions necessarily impact the person once the activity finishes. While that may be the case for some dysfunctional individuals, most people will not be compelled to quit their job and bunker themselves up in their room after reading a Reddit post.