Because no spam fighting measure is more important to us than protecting the content of our users, we've implemented a number of safeguards to make sure that any mistakes made by the classifier can be corrected. This involves presenting CAPTCHAs or other warnings to the user with instructions on how to contact support to resolve the issue. Our support team usually fixes these problems within one business day.
For certain types of blogs - a fraction of those classified - if we receive no response from the user after a significant period of time, we will mark the site for removal. Even when a blog is in this state, the actual content can still be retrieved and the blog restored for a period of several weeks. We've also put additional warnings in the Dashboard for blogs in this state so that the problem can be corrected quickly.
The steps we've taken have both improved the quality of content on Blog*Spot and improved the Blogger service as a whole. By taking steps like this, we're able to dedicate more storage, bandwidth and engineering resources to our users instead of spammers.