It is too simple to blame all our economic problems on the greed, incompetence and amorality of one occupational group. Yet Britain's bankers repeatedly make it hard to recall that the financial-services sector can make a positive contribution to society.
The week before last, the publicly owned RBS, which includes NatWest, updated some software only to find that it stopped working. The frustrations of customers were not assuaged by the vast salaries paid out of public money for the supposedly unique managerial skills of the people charged with turning the bank round.
Last week's £290m fine imposed on Barclays for cheating the market in inter-bank lending was a different kind of shocking. You do not need to know the finer workings of the money markets to be outraged by the brazen dishonesty of traders disclosed in the emails.
The losses suffered from the manipulation of inter-bank interest rates may be diffused among many parties to those markets, but you do not need a degree in higher mathematics to know that insiders were abusing their position at the expense of outsiders.
This is especially damaging to the reputation of the banks, whose business is already widely regarded as being built on exploiting customers, in one recent case described as "muppets".
The next scandal, reported the next day, was the mis-selling of interest-rate swaps as a form of insurance to small businesses. In some ways, this outrage was even worse. While manipulating inter-bank interest rates was a sharp practice that managers could not explicitly condone, selling duff products was a matter of overt corporate policy.
Unsurprisingly, Ed Miliband, the Leader of the Opposition, has called for an inquiry into the banks similar to the Leveson inquiry. In The Independent on Sunday's view, such a public inquiry would be a waste of time and money. What is needed is for the regulators to do their job and for criminal prosecutions to follow.
If the Serious Fraud Office needs more money to make sure that the law and the rules are enforced, then we have some suggestions for where that could come from, starting with the £290m fine - a fine that will otherwise go back to the banks other than Barclays by reducing their subscription to the Financial Services Authority.
And if George Osborne, the Chancellor, persists in saying that Labour failed to make manipulating the inter-bank interest rate a criminal offence, then he should obtain new legal advice about obtaining property by deception.
Indeed, Mr Osborne's attempt to blame Labour's "light-touch" regulation was more generally absurd, as the Conservative criticism of Labour, until 2008, was that its regulation of the City was not light-touch enough.
We understand the Chancellor's desperation to blame others, however, even if we do not condone it. He and David Cameron well appreciate the danger of last week's revelations to their careers. Once again, they find themselves impaled on their slogan, "all in it together". We know that most of the Cabinet, including Nick Clegg, are, by upbringing, habits of thought and interest, of the same class as the bankers.
That means that they have to ensure that the response to wrongdoing in the banks has to be even more draconian than it would be under Labour. If they do not follow through on last week's rhetoric of condemnation, they will deserve to lose the people's trust for good.