Beating the system
Hah! I got the better of google reader. I put something in blogger that was meant to be a draft earlier. However, I accidentally hit the publish button instead of the save button. I raced back and saved it to a draft to take it down, but I knew that this wasn't going to prevent it going out to readers (I have learnt that the hard way). So instead I just copied the contents of the post to create another one later, deleted the content, then hit the publish button again (but leaving the actual post there and not deleting it in entirety, which also doesn't prevent it going to the readers or being updated if it has already made it to them). And it worked. That is why there is that empty post below. As far as I have been able to determine, that is the only way to madly stop something going out to all the readers that you didn't want to (once you have hit that publish button), or to make readers update a post to remove the content if it is already there.