Taiwan Easycard: risks and rewards on one card

Beep, and a smart card gets you on a bus.
Beep, and the same card opens your office door. Beep, and you buy your coffee at a corner shop. Beep, you pay for parking, open the exit gate. Beep, check out a library book.
Beep. Beep. Beep. At school or university, the card becomes your ID.
As Taiwan's capital, Taipei, wakes and the sunlight strikes its skyscrapers, the members of one family make sure their wallets contain one important thing - Easycard.
"We really can't go about without it, all our life depends on it," says Wenney Tsai, as she prepares breakfast for her husband, Jerry Huang, and children, Chelsea and Jonathan.
Taiwan introduced its smart card - equipped with radio frequency identification (RFID) tag - in 2002, following the examples of Hong Kong, Japan and Singapore.
The card was first used on buses and Taipei's Tube, the MRT.
Then it expanded to cover high-speed rail, which connects the capital with the south of the island, and some taxis. You can also use it at hospitals, shops, to rent a bicycle and even on domestic flights.
Today, Easycard is one of the world's most multifunctional smart cards. Other cities are now considering equipping their citizens with something similar.
So, what should they know about its benefits - and potential pitfalls?
Even hospitals in Taipei accept the card - but some people worry about security and privacy issues
Convenience and safety
"Good-bye, Chelsea." Ms Tsai drops off her 11-year-old daughter at a primary school in central Taipei.
The little girl quickly disappears, but moments later her mother's mobile phone beeps.
"Your daughter is safely at school," reads a text message sent to Mrs Tsai.
As soon as Chelsea touches her Easycard to a sensor at the entrance to the school, her mother receives a message.
Most schools in Taiwan's capital use the RFID technology, both to track students' attendance and to "reassure parents that their children are safe", says Chelsea's father.
"Chelsea can also buy something if she wants to - we put 200 New Taiwan dollars [($NT) (£4; $7)] on her card."
Hundreds of shops around Taiwan, and especially supermarket chains 7-Eleven and Family Mart, are equipped with the Easycard payment system.
The technology reduces the amount of cash in the till, which discourages robbers, according to Family Mart.
Security and privacy
So how does it feel - being able to control so many aspects of your life with just one card?
"It's convenient - this way we don't have such a fat wallet," says Mr Huang.
He even has his credit card integrated with the Easycard. Now, he says, he can go way above the usual spending limit of the smart card, fixed at $NT10,000 (£214; $336).
If he were to lose it, he would immediately call his bank - which in turn should notify Easycard.