Fiddling around with ring-fences isn't enough. To organise investment for social benefit; to redress inequality; to give any reforming government the means it needs to fend off the pressure of global financial markets - there is no alternative but to expropriate the banks and high finance.
They should be converted into a public banking, mortgage, and pension service, under public ownership and democratic and workers' control.
The last five or six years have indicted the banks. Even the conservative Financial Times columnist Martin Wolf admits, though without drawing full conclusions, that: "Banks, as presently constituted and managed, cannot be trusted to perform any publicly important function, against the perceived interests of their staff [meaning their top bosses, not the routine clerical staff]. Today's banks represent the incarnation of profit-seeking behaviour taken to its logical limits, in which the only question asked by senior staff is not what is their duty or their responsibility, but what can they get away with".
Yet the banks control the bulk of the fluid, mobile wealth in society. They stand at the crossroads where investment decisions are made.
The control of investment funds by the banks makes it apparently not "realistic" to invest in health, education, welfare, and other public services, but very "realistic" to invest the £38 billion currently being put by property developers into building new luxury housing in London at an average of £2.5 million a dwelling.
Banks are also a vast engine of inequality.
After being bailed out by the taxpayer in 2008, banks made about £35 billion profits last year. That is a sum comparable to the total cuts planned by the coalition government in education and welfare for five years.
The banks and other financial firms paid out £13 billion in bonuses in 2011-2. That £13 billion, plus £7 billion from the huge salaries paid to top bankers, would be enough from one year to cover all the £20 billion cuts the coalition has planned to the NHS over five years.
The economic crisis which exploded in 2007-8, and still lumbers on, was generated by the collapse of an ever-more-precarious spiral of profit-seeking gambits by the banks. Now more and more scandals come to light.
Banks were rigging the Libor interest rate - the published benchmark rate at which banks borrow from each other - and thus skewing huge numbers of financial transactions across the world which use that benchmark.
Barclays, RBS, and the Swiss bank UBS have agreed to pay fines for the rigging. Investigations continue. Under pressure, chancellor George Osborne has pressed RBS to deduct the cost of the fines it has paid to US authorities from the bonuses it pays to top bankers. After taking part in the biggest financial scam in history, the bank bosses don't personally get fined, or sacked, or jailed: some have their bonuses reduced, and that's all.
British banks have been forced to set aside £12 billion for compensation payments to those mis-sold payment protection insurance (PPI). The Financial Ombudsman Service received 180,679 new complaints between October and December 2012 on PPI.
Barclays, HSBC, Royal Bank of Scotland and Lloyds have also had to set aside £700 million so far for compensation for mis-selling complex derivative products like interest-rate swaps to small businesses.
Barclays is being investigated about claims that, in 2008, it made a loan (i.e. from the money deposited with it by customers) to the government of Qatar so that Qatar, in turn, could buy Barclays shares, and then the bank could claim that it had enough of its own funds to avoid the annoyances of a state bail-out.
None of those scandals can be explained away as an understandable blunder of immaturity. These banks have been operating for hundreds of years. In the years running up to the crisis in 2008, both bankers and governments assured us again and again that the management and regulation of banking had reached near-perfect excellence.
It is in the nature of capitalism that bankers always push into ventures which offer extra profit. They know some will go wrong, or be found out - but then they'll pay a fine and carry on. That's business.
In 2008 the British government, like others, poured vast quantities of cash, credit, and guarantees into the banks to keep them afloat: a total of £1107 billion, something like the equivalent of £18,000 for every child, woman, and man in the UK.
There was much talk then of a radical improvement in the regulation of banks. Very little has come of it. Lobbying by the bankers has made the new regulations looser than was predicted in 2008.
Banks were nationalised then, but that just meant that the government put money into them and left much the same bankers running, on exactly the same criteria as before. It was more like "compensation without nationalisation" - without any public control, that is - than the old socialist demand of "nationalisation without compensation".
A few bankers have resigned - like Barclays boss Bob Diamond, with a "golden goodbye" of £2 million - but mostly the top bankers are still shamelessly taking home truckloads of loot.
They are confident enough to voice outrage when chancellor George Osborne, under pressure from MPs, says that he will legislate so that if banks break new rules about ring-fencing their investment banking (large-scale dealing in financial markets) off from their retail banking (their "High Street" business), then they can be forcibly divided into separate investment-banking and retail-banking businesses. Penalised for breaking the rules! That shouldn't happen to us, say the bankers!
The TUC should dust off the policy for "full public ownership of the [banking] sector and the creation of a publicly owned banking service, democratically and accountably managed", decided by its congress last September, and campaign for it. Unions should press for the Labour Party to take up the demand.