I have seen a rather clever prompt by a large software publisher to change my search engine and start page and almost clicked "Yes". For most of non technical users, it may be really troubling and they may even blame Firefox (updates) for the change.
Story/comments are there:
I wonder if it is possible to display a non obtrusive prompt like "Know your rights" when first launched to inform user that their search engine and/or start page has been changed since last launch. Perhaps an option to revert them to their original ones? The idea is to warn and offer "fix" option but not to break the workflow. E.g. no popups etc.