Internet banking offers that same immediacy, when it works.

But what if you suddenly can't lift the mattress or your combination code doesn't work? Online, where the internet is both the means to withdraw funds and the medium to spread the rumour that triggers a run, the answer is pandemonium.

Northern Rock customers last weekend showed that a 'digital dash' on an online bank can create a sense of panic just like a more traditional run on the local branch can. Northern Rock has weathered the credit crunch with a bailout from the Bank of England, but its experience may have tarnished the reputation of the electronic banking facilities European institutions have spent nearly $3bn to create over the past three years, according to analyst firm Datamonitor.

"People sometimes need to be reminded that it's more than just a computer dealing with their query at the other end, and the fact that queues outside branches still persisted even after the Bank of England stepped in to help Northern Rock shows there was psychological damage, " said Patrick Shallow, managing director of Finanalysis, a Dublin banking consultancy.

NOW the question is whether the sort of people who were scared into queueing at Northern Rock branches when they couldn't check on their money any other way will trust it again.

"Being honest, it [Northern Rock's online problems] doesn't help the reputation of internet banking, and it's certainly been a wake-up call for the sector, " said Greg McAweeney, general manager of internet bank RaboDirect.

"Many banks, particularly in Ireland, have underestimated and underinvested in e-banking and it's only in the last 18 months that they've invested in proper functionality, but there still needs to be investment in infrastructure to prevent this kind of thing."

Just over one million of Ireland's 1.8m payment accounts were internet-enabled in 2006 according to the Irish Payment Services Organisation, and as more purely online banks offer their services in the Republic and increasing broadband penetration drives take-up of e-commerce in general, this figure is set to increase. For example, more than 750,000 of AIB's customers are "regular" users of e-banking facilities, and last month there were more than four million online logins for the first time.

"The internet has become a key delivery channel, but some banks are skewed to over reliance on it. Clicks and bricks is still the best model, " said Sean Jevens, head of echannel development at AIB.

Bank of Ireland has 650,000 registered online customers, and turns over 5m in online transactions per year, a 52% increase on last year.

Ciaran Kelly, partner at PWC, expects this to be the norm as established banks continue to take advantage of the internet, possibly to the detriment of purely online enterprises. "I think in light of Northern Rock, if you were to start up an internet bank in the morning you'd be in trouble, but the major banks and online banks with a lot of weight behind them won't have too many problems." For Northern Rock, Britain's fifthlargest mortgage lender, its online channel was put under immediate and sustained pressure when thousands of customers, concerned that their accounts would be affected by the current liquidity crisis rocking global markets, tried to access and withdraw funds from their online accounts after the media highlighted the bank's credit problems.

It's important to note that it was the internet that also started the process, as reports that the Bank of England had intervened in Northern Rock first appeared online, causing lines to form outside British branches before the breakfast time broadcasters had covered the story, and prompting a reported �350m to be withdrawn online before Northern Rock's electronic systems were overwhelmed.

The bank's website buckled under the weight of requests, many of which came from Northern Rock's 25,000 Irish customers who have no high street branches to picket as in Britain, and concern turned to fright as scores of customers posted their frustrations on financial discussion forums and blogs, themselves adding to the cycle of online nearhysteria amongst a group used to instant information access.

"I am Northern Rock customer - I'm not sure whether to be scared, bemused or angry right now, " is one representative comment left on a blog last week by a retail saver who couldn't access his account online.

A spokesman for Northern Rock said stock exchange rules prevented the bank from disclosing how much cash was withdrawn over the counter at its 74 British premises and Dublin office, however it is likely the majority of the estimated �2.2bn withdrawn from Northern Rock since last Friday was transacted on the internet.

Northern Rock's website reportedly slowed to crawling speed under the weight of requests it had to handle (or it was slowed down deliberately some commentators have claimed, a charge denied by Northern Rock) and observers noticed an immediate trend develop: worried customers who could not contact Northern Rock or access their e-banking accounts began posting their queries on financial discussion websites and blogs. Thus, just as photographs of queues outside Northern Rock in England depict customers talking to each another, no doubt discussing their particular dilemmas, online customers also turned to one another for advice and support, showing that evolutionary biologists' theories on the human predisposition to the 'herd mentality' operates in cyber space as well as on the prairie.

Brendan Burgess of financial discussion website Askaboutmoney. com makes the analogy of being on a jet when it has technical problems "and the guy sitting next to you is an aeronautical engineer who says 'don't worry, this aircraft runs fine on only three engines' . . . it's reassuring, and online discussion forums give people access to expert opinion and shared experience nearly instantly."

Burgess also feels specialist chat forums are frequently ahead of the mainstream media as niche experts often foresee impending financial difficulties whereas newspapers are more likely to react after the fact. "A month before Northern Rock hit the headlines, posters on Askaboutmoney were noticing unusual pricing on Northern Rock short stops, pointing out Moody's investment rating of Northern Rock was AA3, but the credit default rating was BA1. This is analysis you can't get in the newspapers, and was a topic that wasn't discussed by the Financial Regulator or [UK] Financial Services Authority at the time."

The airline analogy is apt as anyone who has been stranded in a foreign airport after a cancelled flight knows it can be somewhat reassuring to have a few souls stuck in a similar predicament. There is a lesson for financial institutions here: just as grumpy passengers can be mollified by an airline rep informing them of why a flight has been delayed or cancelled, so too can the banks keep a lid on unfolding panic by having an instantly accessible presence online.

A senior official at a large Irish bank said this development had been noted: "What Northern Rock showed us is that it's important to keep an eye on these discussion boards, and if there is uncertainty expressed by our customers then engage with them online. . . even just a general, honest message stating we are aware of whatever the problem is, like a malfunctioning website, reassures people that we're trying to get it sorted, " she said. "After all, a bank's main intangible asset is trust."

"The big shift now is how these big organisations deal with their online audience, " said Irish political blogger Mick Fealty of SluggerOToole. com who is researching the internet's effect on political process. He said the internet has as much as an acceleratory and focusing effect on financial discussions as it does on political discourse. "How can they engage with something as anarchic as the blogosphere is the real question. The 1929 Wall Street crash was exacerbated by rumour, but this was confined to a certain financial elite. The internet widens that pool of opinion formation. . . it is more democratic."

The banking sector will have to study these developments. Electronic banking on the internet can create not only great efficiencies in terms of administration of accounts, but also has the possibility to become an accelerator for knocking confidence in a bank's stability. Being aware of this will keep customers from fondly remembering the mattress.