When HM Revenue & Customs haemorrhaged the personal and financial information of 25 million British families in November, wags dubbed it the "Privacy Chernobyl", a meltdown of global, epic proportions.

The metaphor is apt: the data collected by corporations and governmental agencies is positively radioactive in its tenacity and longevity. Nuclear accidents leave us wondering just how we're going to warn our descendants away from the resulting wasteland for the next 750,000 years while the radioisotopes decay away. Privacy meltdowns raise a similarly long-lived spectre: will the leaked HMRC data ever actually vanish?

The financial data in question came on two CDs. If you're into downloading movies, this is about the same size as the last couple of Bond movies. That's an incredibly small amount of data - my new phone holds 10 times as much. My camera (six months older than the phone) can only fit four copies of the nation's financial data.

Our capacity to store, copy and distribute information is ascending a curve that is screaming skyward, headed straight into infinity. This fact has not escaped the notice of the entertainment industry, where it has been greeted with savage apoplexy.

Wet Kleenex

But it seems to have entirely escaped the attention of those who regulate the gathering of personal information. The world's toughest privacy measures are as a wet Kleenex against the merciless onslaught of data acquisition. Data is acquired at all times, everywhere.

For example, you now must buy an Oyster Card if you wish to buy a monthly travelcard for London Underground, and you are required to complete a form giving your name, home address, phone number, email and so on in order to do so. This means that Transport for London is amassing a radioactive mountain of data plutonium, personal information whose limited value is far outstripped by the potential risks from retaining it.

Hidden in that toxic pile are a million seams waiting to burst: a woman secretly visits a fertility clinic, a man secretly visits an HIV support group, a boy passes through the turnstiles every day at the same time as a girl whom his parents have forbidden him to see; all that and more.

All these people could potentially be identified, located and contacted through the LU data. We may say we've nothing to hide, but all of us have private details we'd prefer not to see on the cover of tomorrow's paper.

How long does this information need to be kept private? A century is probably a good start, though if it's the kind of information that our immediate descendants would prefer to be kept secret, 150 years is more like it. Call it two centuries, just to be on the safe side.

Photo: Getty

Weapons-grade data

If we are going to contain every heap of data plutonium for 200 years, that means that every single person who will ever be in a position to see, copy, handle, store, or manipulate that data will have to be vetted and trained every bit as carefully as the folks in the rubber suits down at the local fast-breeder reactor.

Every gram - sorry, byte - of personal information these feckless data-packrats collect on us should be as carefully accounted for as our weapons-grade radioisotopes, because once the seals have cracked, there is no going back. Once the local sandwich shop's CCTV has been violated, once the HMRC has dumped another 25 million records, once London Underground has hiccoughup up a month's worth of travelcard data, there will be no containing it.

And what's worse is that we, as a society, are asked to shoulder the cost of the long-term care of business and government's personal data stockpiles. When a database melts down, we absorb the crime, the personal misery, the chaos and terror.

The best answer is to make businesses and governments responsible for the total cost of their data collection. Today, the PC you buy comes with a surcharge meant to cover the disposal of the e-waste it will become. Tomorrow, perhaps the £200 CCTV you buy will have an added £75 surcharge to pay for the cost of regulating what you do with the footage you take of the public.

We have to do something. A country where every snoop has a plutonium refinery in his garden shed is a country in serious trouble.