When I had to reconnect my Mozilla account to 2 different versions of Firefox I didn't expect that Firefox would have opened a tab for all the extensions that it was installing from my account. It would be helpful if Firefox warns beforehand that the synchronization will automatically download all the user's extensions and that it might open a tab per extension. Because to users who have never done a sync before seeing so many tabs suddenly open without warning seems like spam or hacking going on 😱😆.