Thank you for the many thoughtful comments in this thread. As several of you pointed out, we do take privacy very seriously, which is what led us to develop the disclosures mentioned above (http://www.google.com/support/plus/bin/answer.py?answer=1319578
) that explain why we send URLs back to our servers and why that helps our users in a safe way.
However, it’s clear from the discussion that our current behavior is not obvious to some of our users. As a result, we have decided to take a more conservative approach and remove some functionality from the extension. Tomorrow, we will be releasing an update that does not
work for https URLs with query parameters. For the geeks out there who want to know more, check out my profile tomorrow for a post with more details. (Update: post now live!).
We’d like to add that functionality back, at least for users who want it, and are looking into options for doing so.