The obvious question to me is: why is Discussion getting this spam where main LW didn't and doesn't?
From the About page:
Users with sufficient karma (+20) can publish posts to the main site, anyone can post to the discussion araa.
(looks like there's a typo btw)
I'm mean most of us would like a friendly bot to chat with, but this is just paperclipping the section (no offence clippy), by now its starting to be a real trivial inconvenience for me and it reduces my desire to check out new topics.