If you have a website with us running HTTPS there's a good chance that the secure certificate was issued by Thawte who are part of Symantec - an organisation who issue about a third of all the certificates in use today . You may also have read about changes that Google and others want made to the way in which Symantec operate summarised on the Symantec site in this blog post.
As a result of this pressure Symantec have agreed to sell all their certificate-related interests to DigiCert - for more information on this sale see the article on ZDnet.
We wish to assure you that we are monitoring developments closely - it's possible that a few certificates may need to be re-issued by Thawte but we will handle that process if it proves necessary and there should not be any impact on you or your site.