This from Boston. The CharlieCard is an Oyster-type pre-paid cardcard
used in Boston. Ditto Octopus in HKG.

Subject: Expiring CharlieCards causing confusion and frustration

http://www.bostonglobe.com/metro/201..._campaign=8315

For frequent riders, the expiration proves largely invisible: Their
cards
get an automatic software upgrade, and two-year extension, when
swiped. But
irregular riders may find themselves suddenly unable to use their
plastic
CharlieCard. ..

A few weeks ago, reader Irene Gruenfeld of Sudbury and her husband
took
their 5-year-old twins on a stroll through the city with a promise of
a Red
Line ride from Charles/MGH back to their car in South Boston. They had
more
than $10 on each of their cards, but the station gates failed to open,
displaying an "expired'' message. The vending machines presented
similarly
cryptic information. No staff was present, forcing them to buy the
paper
CharlieTickets spit out by the machine, which cost 30 cents more per
ride.

When the CharlieCard was introduced, five years was the industry
standard
for the still-emerging smartcard technology. Manufacturers at the time
recommended a programmed "sunset date'' to stave off problems that
might
arise from frequently used cards nearing the end of their useful life,
he
said. As it became clear the cards could last longer, more recently
issued
CharlieCards have been given sunset dates of 10 years. Most of the 6
million
issued have the longer lifespan, he said.