It's a minor annoyance but hopefully an even more minor fix. I suggest that the site code be modified such that entirely empty nodes are automatically rejected. It's a particular time-and-resource waster in the case of anonymous posts as they serve absolutely no value - would anyone dispute this?
There might conceivably be some argument for allowing empty non-anonymous posts (although what it might be escapes me) so that could be up for debate. If you think these are worth allowing then do please contribute to this thread.