Some 7,000 miles (12,000 km) away, in the Chinese city of Guangzhou, another student has facial payment technology on her mind. Ling (who did not wish to share her real name for fear of getting into trouble) says that it is now the only way to buy food from the vending machine in her accommodation block at Sun Yat-sen University.
However, charity shops are better prepared this time, Mr Osterley said. Take for example Stockport hospice charity, Beechwood Cancer Care. There's been a queue of customers at its Heald Green precinct. But it is only open to shoppers, not droppers, this week.