You might have thought Facebook had faced enough controversy over making changes without warning. However, there is a fresh outcry as it emerges that it has changed every user's contact email to a Facebook one - ending @facebook.com.
So why has this happened, and what can you do about it?
The changeThe contact information is controversial, because some experts have raised privacy concerns that it enables anyone to see your address, phone number and email address. In the wrong hands this could open up users to the risk of everything from burglary to ID theft.
However, there are those people who consider it a vital part of their Facebook profile - enabling people to get in touch with them. It helps reconnect old friends and colleagues in the real world rather than just online.
Those users have had an unpleasant shock today, as Facebook removed the personal email address of all its users and replaced it with a Facebook one. It means anyone trying to email would end up sending you a Facebook message instead.
The reasonsFrom the site's point of view, Facebook argued that the move would protect privacy. However, it can't have escaped their notice that it also keeps people tied to the site. It stops Facebook friendships moving off the site into personal emails, where the users can no longer generate page views and advertising revenue for the company.
So what can you do?If you want to revert to an old email address, you can do so by switching it manually. You need to access the 'about' section of your profile. Then click on the word 'edit' next to your email address. Click next to your Facebook email address and change to 'hidden from timeline' then click next to your preferred email address to change it to 'shown on timeline'. Then save and close.
However, it is worth thinking twice before you do this. Are you happy having an email address so public? Have you protected your contact information from prying eyes? And do you mind emails coming via Facebook? Because while this may feel like unwanted interference, it may just help protect you online.