Matt Cutts of Google wrote an entry named How Google handles hacked sites. In that post he details on specific example of a site that was hacked, spam was placed on the site, the site was dropped from the Google index, and the site owner was upset and the story made it to Slashdot. Due to that, Matt felt it appropriate to explain how Google typically handles these types of issues, using that site as an example. You can see how the site was hacked, the type of spam placed on the site, the date Google dropped the site from the index, the dates Google tried to notify the site owner via Webmaster Central and via email and the approval of the reinclusion request. Matt’s post is well worth a read.