The more I think about it the more the whole unnatural notice/penalty thing really makes no sense to me.
If they really wanted people to stop building unnatural links without skewing linking on the net due to the gross overreactions of so many who receive WMT notices and then remove anything at all questionable and likely tank their site in the process, all they would have to do is say:
"3147 links from example.com to your site have been ignored due to them looking unnatural. If you have built these links we're notifying you they aren't doing any good and neither will any similar links built in the future.
If you did not build these links then you can ignore this notice the same way we have already ignored the links previously noted which are pointing to your site."
People who got a notice like the preceding and were building links would likely stop as soon as they realized it was futile. People who didn't build the links or only had "unnatural links" from one site or to one page wouldn't overreact and remove/disavow everything.
It would be better for everyone, including them if they're really trying to rank the right page(s), because the overreactions of webmasters receiving Google's current FUD notices are skewing links in the opposite direction and Google is likely causing a decline in their own quality, since they use link churn, link growth rate, freshness (based in part on links), PageRank and other link based factors in their algo.
I'll end my rant about their seriously bad idea of unnatural link notices and penalties now.
[edited by: TheOptimizationIdiot at 1:01 am (utc) on Apr 3, 2013]