Silvery - 3:06 pm on Oct 18, 2010 (gmt 0)
From a number of us local search marketers who trade info with each other, we believe that Google is indeed paying attention to both listings and reviews complaints. However, we theorize that they seem to use an algorithm to "triage" the listing, so listings with more complaints get addressed first.
It appears that possibly "super-reviewers" get preference and/or listings with more reports of issues from a handful of users may get bumped to the top of the queue.
For issues like this one where they won't see any evidence of issues, they could choose to do nothing. If the reports of extortionary demands increase, they might be able to coordinate which accounts are coming up frequently, and see enough pattern to suspend them all. I found such a pattern of fraudulent reviews recently and reported it to them -- very transparent and easy to identify.