Well, it definitely means you have far more at stake every time you comment or participate, since you're putting your reputation on the line and creating a public record.

However, I ultimately don't think requiring IDs would be effective and it would probably expose at-risk and vulnerable groups to greater retaliatory action. It's arguably a bit classist as well, since only those who are sufficiently rich and powerful enough to protect themselves would be able to participate with impunity.