You're right. I don't have a good solution, but maybe somebody finds out something.
Because something has to be done before it gets too big to be contained.
We're talking about one case right now, correct?
Or is there a whole list of feedbacks of this type (and if, is there more than one account, and more than one service utilizing it?)
I'd contact an admin and suggest removing that specific feedback as it's "spam" (advertisment) in some way.