jmccormac - 3:11 pm on Apr 18, 2012 (gmt 0)
@backdraft7 The thing that most people don't see with the web is that much of it is brochureware (I include Google in this as that Wikipedia with a shopping cart blog post is quite worrying in its level of cluelessness). This means that the sites are very often fire and forget ones for small businesses where the web developer's involvement ends when the site goes online and the customer is happy. However it is these untended brochureware sites that will often have out of date plug-ins. The owner is very probably non-technical and may even be unaware that their site has been compromised. Not every site owner is a web developer.
@BillyS It might be a blanket e-mail but given the way that Google has banjaxed things with Adsense and Panda, it might not be worth risking a penalty.