Another day, another survey about how bloomin' stupid we all are at basic computer security.

Today it's the turn of wackily named financial advertising agency @www, who are slapping our wrists for writing all our passwords down in marker pen on our hands or on little PostIt notes on our monitors.

Apparently, one in four consumers keep their PIN details in their wallet, and the rest of us are being as lax as a tin of prunes with our passwords.

The survey reveals that one in ten of us has to memorise information for more than 50 'secure' accounts. As a result we – I mean 'they' – jot down their passwords and keep them within 10 feet of their desks, or in our/their wallets.

60% admitted using the same numbers or words for multiple accounts.

Two thirds of those who carry their PIN codes with their cards said they take the precaution of jumbling the numbers up. Surely this is both insecure and very confusing. "I can't remember my PIN number, but it's either 1234, 4321, 1324, 4321, 2341, er…, er…"

By the time you've worked it out even the shady guy looking over your shoulder would have walked away.

Barnaby Hobbs, UK general manager of @www, says people are struggling to cope with the "exponential" growth in the number of companies requiring personal security data: "We are drowning in PIN numbers and security codes," he said.

His solution: learn a new password or PIN every three months.

The dummies surveyed also highlighted difficulties with back-up security questions used to verify PINs or passwords.

Most of us can't remember our mother's maiden name, first school attended or even our pet's name! God knows how we remember the sites' web addresses or which bank we use.

What a sorry lot we are. Can we really blame this incredible lack of memory on the rise of Internet insecurity, or is there really some truth in the hoary old mobile-phone radiation story?