I think that, yes, it would be difficult to enforce possibly in a timely manner, but my sense is that you could have a hundred cases or a thousand cases, but if one comes to your attention, and an action is taken, you can bet it would be widely publicized. So then it becomes part of common knowledge of ordinary individuals that there are certain things you can't do, and that would, in itself, cause self-policing on the part of individuals.
On February 26th, 2009. See this statement in context.