They buy plane tickets and use the boarding passes to enter the transit areas of Changi Airport, but not to catch a flight.
Instead, they want to catch a glimpse of their idols or beat the queues to get the latest launch products, like the iPhone 7.
A handful buy the tickets to remain in the transit areas to spend more time with a family member or friend leaving Singapore.
They are all breaking the law.
A total of 59 people have been arrested for misusing their boarding passes in the first half of this year, almost triple the 22 arrests for the whole of 2015 and the 23 seen last year.
"People who misuse boarding passes are detected when they exit via the immigration channel," said a police spokesman.
The Sunday Times understands that many of them purchase tickets from budget carriers such as Scoot and Tigerair because they tend to be cheaper.
A one-way ticket on Scoot from Singapore to Jakarta next month, for instance, costs $40.
Airlines say they are not able to differentiate cases of abuse from other "no show" cases.
Generally, all "no show" cases - including passengers who have checked in and have been issued boarding passes, yet do not show up for their flights - are reported to the airport police.
Said Mr Robin Goh, spokesman for Jetstar Group: "From an airline's perspective, a passenger with a boarding pass who does not appear at the gate for his flight does not immediately mean a misuse of his boarding pass. This is for the authorities to ascertain."
He said Jetstar has had a handful of passengers who have not shown up for their flights and deemed to have misused their boarding passes by the authorities in the last decade.
Scoot and Tigerair said they do not keep track of passengers who purchase one-way tickets and do not show up as this is not considered a breach of security.
While not showing up is not an offence, misusing the boarding passes warrants a police investigation.
Earlier this month, a 28-year-old man was arrested for misusing his boarding pass and entering the transit area of Changi Airport to see his friend off. He had no intention to depart Singapore.
In May this year, two female students aged 16 and 19 were arrested for buying air tickets in order to meet their idol, South Korean hip-hop artist Simon Dominic, in the Changi Airport transit area. He was coming to town for a concert.
Last September, a man and a woman were arrested here for using their boarding passes to enter the transit area to purchase the iPhone7. Then, the phones had just been launched and there were long queues at retailers outside the airport.
There are signs placed outside the transit areas that urge passengers to use the correct passport and boarding pass for entry and to proceed to the next destination.
However, those that explicitly warn passengers that misusing boarding passes is an offence are flashed on electronic screens above the check-in rows, before passengers have shown their passports and boarding passes to officers to gain entry to the area.
The police said those who misuse their boarding pass to enter the transit areas, with no intention of proceeding to their next destinations, can be prosecuted in court.
If convicted, they can be jailed for two years or fined $1,000 or both.
The police declined to give details on cases that have been prosecuted and the penalties that have been meted out.
The Sunday Times understands that a number of those people caught misusing the passes were unaware that doing so constitutes an offence.
Said cleaner Siti Anurlan, 66, who sent her friend off at the airport last Tuesday outside the transit area: "I haven't seen such signs and I think most people don't know that they will get in trouble for going in and not flying."
Correction note: This story has been edited for clarity.