A Google Groups thread discusses the ramifications content warning pages have on search engine visibility. See, if your blog has questionable content, the Google Blogger platform will put up a warning page. However, the problem is that this page itself impacts visibility in the search engines substantially. The problem is described here:

So what happens now? JohnMu acknowledged that Google is aware of the issue, but there’s no fix for it just yet.

Forum discussion continues at Google Groups (#1) and Google Groups (#2).