Most bank account holders have heard of card skimmers, the insidious devices that steal your details from inside a cash machine.
Now, however, there is another danger to watch out for at the hole-in-the-wall - the 'cash trap'.
The simple, claw-like implement sits inside the slot that dispenses notes and grabs hold of customers' money until the thief returns to collect the loot.
Invisible crime: Claw-like cash trap devices, which are inserted into ATMs to grab cash before it can be dispensed to the customer
Rife: The simple contraptions inserted into cash-dispensing slots have been spotted in Lincolnshire and across Europe
The devices have been used at cash points across Britain, with 2,479 reported cases in the first half of 2012.
Fraud losses through cash trapping and other ATM scams across the UK came to £29.3million last year, according to Financial Fraud Action UK, although this is said to be dropping since chip and pin was introduced in 2004.
Such scams are already rife across Europe. Thieves stole more than a million euros from French cash machines this year using devices that prop open note-dispensing slots, according to security experts.
Police have warned account holders to be vigilant, but many devices are impossible to spot.
Some are designed to look like part of the machine and attached to the front, and others - such as the claw - are completely hidden inside the ATM.
This can mean that customers remain unaware of the problem and simply assume there is a fault with the ATM, failing to report the crime.
Jaws: cash trapping device is shown removed from the machine. Police have warned customers to look out for anything unusual at ATMs
The European ATM Security Team advises customers to immediately report all incidents to the bank.
In August, Lincolnshire Police issued a warning to cash machine users after fraudsters tampered with three machines in Spilsby and Louth, pocketing hundreds of pounds from one transaction.
Officers warned anyone who spots anything unusual on an ATM, finds a device or notices part of the machine falling off to contact the police as soon as possible.
A SERIES OF SCAMS
A spokesperson for the force said: 'Unfortunately, there was insufficient forensic and CCTV evidence [in Louth] to progress the investigation and no arrests were made.
'The Spilsby incidents related to ATMs possibly being tampered with and no actual thefts occurred.
'The banks don’t always notify police in these cases if no crime has taken place and their own fraud departments investigate the matter.
'ATM tampering is obviously a nationwide issue and we work with the banks to raise awareness and educate the public about how to protect themselves from fraud and what things to be on the lookout for.'
Most of the crimes apparently take place outside of normal banking hours.
A spokesperson for EAST said: 'The criminals operate by cash being collected by a customer. As far as a customer is concerned everything can be going fine with their transaction and the receipt - if they get one - can say "£20 taken out", but they've got no money.
'The cash trap is normally placed across the front of the cash dispensing slot, either with adhesive or a spring. The claw is one variant, which is placed inside machine and is a little more sophisticated.
'The criminals make one transaction and insert the device while the slot is open.
'We saw a significant increase in these attacks in 2011, with 15 European countries reporting such crimes, and a surge in the second half of the year.
'The success of chip and pin seems to be driving criminals from high-tech card skimming to low-tech techniques such as cash trapping.
'This can be combined with other ways of manipulating the ATM.'
It is estimated that in the first six months of 2004, more than £40.5million was fraudulently taken from customers' accounts using card skimming in London and the South-East alone.
In March 2005, Dover-based Kenneth Mennie had £1,500 stolen from his Lloyds TSB current account after his debit card was copied and used in Thailand.
Four months later, five Romanians stole up to £1.2m by sticking false fronts to ATMs across London to skim unwitting customers' cards and film their PIN numbers being entered.
A laptop found at the gang's safe house contained details of 1,236 bank cards.
It is believed most of the cash was channelled to Romania in a 'fruitful and sophisticated fraud'.
Helping themselves: Thieves stole more than a million Euros from French cash machines this year using a similar technique, pictured, in which cash-dispensing slots are propped open after normal transactions
Since the advent of chip and pin, however, cash traps may be the most worrying trend, because they are simple, cheap and spreading fast.
Earlier this year, industry experts reported on the danger of 'robbing by radiowave' - in which thieves access 'contactless' cardholders' details simply by walking past them in the street and activating a handheld machine.
A spokesperson for Vocalink told MailOnline they had seen a move back to more traditional methods of fraud such as shoulder surfing since chip and pin came in.
Cardholders who are given a contactless card when their old one expires can unknowingly surrender their details to a thief by simply walking past them in the street.
The technology in the card, known as radio frequency identification (RFID), transmits bank details via its own radio signal, and is accepted in many High Street chains, including Co-op, Boots and Pret-a-Manger.
Lucrative scam: A simple fork, pictured, can be placed inside the machine to hold it open after customers have left
It does away with the need for a customer inputting their PIN when buying goods, and was designed to reduce queues at the checkout.
However, a fraudster with a contactless cardreader can easily collect the 16-digit credit card number, expiry date and name – known as RFID skimming – from anyone who walks past carrying one of the new cards.
They then have enough information to rack up huge bills at any internet shopping site that does not demand the three-digit security code on the back of the card.
David Maxwell, a former policeman and director of RFIDprotect, a firm which specialises in protection against card fraud, said: ‘It has been a big problem in America for a while and is getting to be a big problem over here.’
Cards can be protected from RFID skimmers by being wrapped in tin foil or being kept in special foil-lined wallets.