A WebmasterWorld thread reports that new installations of the popular blogging software, WordPress, is by default blocking all search engines.
He said, when you go to the Privacy Options section in the administration panel, by default, it is set to block all search engine robots from crawling the blog. He said, by default, this option is selected:
I would like to block search engines, but allow normal visitors
At one point, Google's Blogger blocked spiders by default as well. I am not sure if Google's Blogger still does, but it did at one point.
There has not been any confirmation made if others have noticing that clean, new installs of WordPress block spiders by default. But there is at least one person reporting so.
Forum discussion at WebmasterWorld.