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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 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.
From 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.
From the users' point of view, this seems like an underhand change made without their permission, which firmly places the needs of the site above those of the user. Twitter users responded to the announcement with anger. One said: "#Facebook's default position on introducing new 'services' seems to be: 'It's easier to ask forgiveness than permission'", while another added "dear #facebook -- what the heck were you thinking? Stupid idea to tweak emails like that w/o warning. Or at all."
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.
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Facebook outrage as it changes users' details
Using a mobile phone to make and receive calls, send texts and browse the web while abroad can be extremely costly – especially if you are travelling outside the European Union (EU), where calls can cost up to 10 times as much as at home.
To avoid high charges, Carphone Warehouse suggests tourists ensure a data cap is in place, use applications to check data usage, turn off 'data roaming', avoid data-intensive applications such as Google Maps and YouTube and use wi-fi spots to update social networking sites.
Payment Protection Insurance (PPI) is supposed to help people to continue meeting their loan, mortgage or credit card repayments if they fall ill or lose their jobs. However, policies are often over-priced, riddled with exclusions and sold to people who could not make a claim if they needed to.
At one point, sale of this cover - which was often included automatically in loan repayments - was estimated to boost the banks' profits by up to £5 billion a year.
Now, though, consumers who were mis-sold PPI can fight back by complaining to the bank or lender concerned and taking their case to the Financial Ombudsman Service (08000 234567) should the response prove unsatisfactory.
It could be you, but let's face it, it probably won't be. In fact, buying a ticket for the Lotto only gives you a 1 in 13.9 million chance of winning the jackpot.
With odds like that, you would almost certainly be better off hanging on to your cash and saving it in a high-interest account.
No-frills airlines such as EasyJet may promote rock-bottom prices on their websites. But the overall fare you pay can be surprisingly high once extras such as luggage and credit card payment fees have been added - a process known as drip pricing.
Taking one piece of hold baggage on a return EasyJet flight, for example, adds close to £20 to the cost of your flight, while paying by credit card increases the price by a further £10.
It may therefore be worth comparing the total cost with that of a flight with a standard airline such as British Airways.
Cash advances, which include cash withdrawals, are generally charged at a much higher rate of interest than standard purchases.
While the average credit card interest rate is around 17%, a typical cash withdrawal of £500, for example, is charged at more than 26%.
What's more, as the interest accrues from the date of the transaction, rather than the next payment date, costs will mount up even if you clear your balance in full with your next payment.
Supermarkets such as Tesco and Asda often run promotions under which you can, for example, get three products for the price of two.
However, it is only worth taking advantage of these deals if you will actually use the products. Otherwise, you are simply buying for the sake of it, which is a waste of your hard-earned cash.
Buy a train ticket at the station on the day of travel and the price is likely to give you a shock - especially if you are travelling a long distance at a busy time of day.
However, you can cut the cost of train travel by 50% or more by going online and making the purchase beforehand - especially if you book 12 weeks in advance, which is when the cheapest tickets are on sale.
Other ways to reduce the price you pay include avoiding peak times and taking advantage of so-called carnet tickets, which allow you to buy, for example, 12 journeys for the price of 10.
Most High Street banks offer packaged accounts that come with monthly fees ranging from £6.50 up to as much as £40, with a typical account charging about £15 per month.
Various benefits, such as travel insurance and mobile phone insurance, are offered in return for this fee. But whether or not it is worth paying for them depends on your individual circumstances.