Google has opened a dedicated thread where you can post examples of poor titles that Google has created in lieu of your HTML title tags. This comes after Google has confirmed the title changes it made to the search results that actually began a week ago Tuesday.

The thread asked you to include the the URL of the page, the title shown, the device type used and any additional feedback, and if possible a screenshot. It does not seem to ask for the query, which I guess is not needed since Google is not using the query anymore for titles.

The complaint thread is located in the Google Webmaster Help forums and you can submit the details there.

John Mueller of Google posted the thread and wrote:

Make sure to post some good examples, Google will be watching but so will I.

Forum discussion at Google Webmaster Help.