I get a bunch of emails like this:
We have recently received a notification from Google stating that our website has unnatural links pointing towards it. This has affected our rankings on Google and as a result, we’re trying to clear things up. Our website URL is www.builddirect.com.
We noticed the following links are pointing to our website from your site:
We understand this is inconvenient and isn’t a reflection on your website at all, but we would like you to make the links “No Follow” or remove the links. This is the final time we will contact you. If you need any more information please do not hesitate to contact me.
I look forward to hearing from you.
The cause of these emails is that Google started penalizing websites for “unnatural links,” and somebody decided the links on that blog were unnatural. These websites may have received a notice like this in Google Webmaster Tools (image via):