Hmmm... What does this mean?

I got a notice in my e-mail, just like the million others...

"dogsandcats has just posted a reply to a topic that you have subscribed to titled 'Give Her heck From Us, Peeves'."

...only "dogsandcats" didn't post anything. The last post is from GinnyWeasleyRocks, back in February.
Curiouser and curiouser.