How Google handles a bug report
Thank you for taking the time to write. We were able to reproduce the issue based on the information you provided, and are actively working on a fix.
We'll announce the fix in the help forum when it's live.
Please accept our apologies for any inconvenience and thanks again for your patience and for taking the time to write.
On March 5th:
Thank you for your reply. This issue should now be resolved.
The root cause was a product issue that in some cases inadvertently shared collaborators between documents that a user selected from their Docs list. Our fix should prevent this issue from recurring.
This morning, Google apparently removed contributors from all suspect Google documents and sent e-mails to their owners:
We wanted to let you know about a recent issue with your Google Docs account. We've identified and fixed a bug which may have caused you to share some of your documents without your knowledge. This inadvertent sharing was limited to people with whom you, or a collaborator with sharing rights, had previously shared a document. The issue only occurred if you, or a collaborator with sharing rights, selected multiple documents and presentations from the documents list and changed the sharing permissions. This issue affected documents and presentations, but not spreadsheets.
To help remedy this issue, we have used an automated process to remove collaborators and viewers from the documents that we identified as being affected. Since the impacted documents are now accessible only to you, you will need to re-share the documents manually. For your reference, we've listed below the documents identified as being affected.
I think Google handled the issue admirably. It was solved within two weeks, they un-shared affected documents and notified their owners.
Of course, this (again) raises questions about cloud computing, as well as Google's eternal beta-status for a lot of their services. At my company, we double check with whom we share our stuff, but we'll keep on using Google Docs. The only (theoretically) safer option for sharing documents is software on our own server, but that won't be bugfree, either.