For example they might identify a football fan betting on a horse race and raise the alarm, missing the fact that it is Grand National day, or block a credit card used abroad during summer holidays.
Treat emails containing attachments or hyperlinks particularly shortened links with caution.
Use your common sense - if an email offer looks too good to be true, the prices on a website are abnormally low or you receive an unsolicited telephone call offering computer support, it's probably a scam.
Mike Lynch, the renowned technology investor who founded software group Autonomy before its $11.7bn sale to Hewlett Packard, has previously invested in the company and sits on its board.
Criminals use online 'fraud forums' to buy and sell credit cards, email addresses and passports.
26% of these attacks were executed internally within organisations.