This week's move by a group of lawyers to take legal action against the New Zealand banks over default fees is not the first time banks have come under pressure.
Legal action on bank default fees was kicked off in the United Kingdom in 2007 after the public began to question the fees they were being charged.
Some banks began to return money to their customers, creating general confusion about what level of fee was acceptable.
The UK's Office of Fair Trading (OFT) - New Zealand's Commerce Commission equivalent - decided to investigate the fairness of terms for unarranged overdraft charges in March 2007.
It agreed to bring a test case involving seven banks and one building society under the Unfair Terms in Consumer Contract Regulations 1999.
The High Court and Court of Appeal found in favour of OFT but it was overturned in November 2009 by the Supreme Court, leaving OFT unable to take the case any further.
Some believe the last-minute reprieve for the banks may have been politically influenced given many of the banks were by then partly taxpayer owned because of the global financial crisis.
While the public's claims went nowhere, the case prompted other agencies around the world to look at bank fees more closely.
New Zealand's Commerce Commission launched an investigation into credit card fees and in late 2009 many of the banks dropped their fees.
Fair Play on Fees campaigner Andrew Hooker, the lead barrister in the case against New Zealand's banks, claims fees have steadily increased since then.
In Australia fees also dropped, but in May 2010 Perth litigation funders Financial Redress and Melbourne law firm Maurice and Blackburn teamed up to take a case against the banks.
The Australian case is being taken in a different area of law to the UK case, giving those behind it the belief that it can succeed despite the failure of the case in Britain.
Maurice & Blackburn have 12 banks in their sights, including the big four: CBA, ANZ, NAB and Westpac, who own subsidiaries in New Zealand.
A test case is being taken against the ANZ and a breakthrough was made in September last year when the High Court of Australia ruled unfair bank fees could be considered penalties.
The case has since gone back to the Federal Court and the key players are awaiting a trial date to be set.
Financial Redress and its parent IMF (Australia) also toyed with launching a case into New Zealand in 2010 but decided not to.
Christchurch lawyer Gary Wakefield discussed taking the case with the Australian litigation funders but says there were issues relating to the class action rules in New Zealand.
Unlike in Australia, New Zealand law doesn't currently allow for class actions to be taken.
A class action is where people have to actively opt out if they don't want to be included in the case. This results in a much bigger suit being able to be taken.
In a representative case like that being proposed in New Zealand people have to opt in to be part of it.
Amendments to litigation rules have been proposed in New Zealand but up until recently there has not been any political action on it since they were set out in 2008.
Justice Minister Judith Collins recently announced she was working on the legislation to enable faster, better and cheaper class suit actions.
Wakefield says there was a combination of reasons why he didn't go ahead with his lawsuit.
"We were unsure whether we would get enough support, we were unsure whether an amendment to the class action rules would be made. There was nothing specific we just put it in the too hard basket."
Wakefield says it is interesting that Hooker is bringing the case now.
"I think legally yes, it's very similar to what has occurred in Australia. I think it has got legs here as well."
He doesn't believe it is necessary for the class action law to be changed here first. "At the moment you can bring a representative proceeding."
He says the biggest risk to taking the case is being hit by adverse legal costs. That risk has been taken away from individuals because it is being worn by the litigation funder but the costs can soon mount up, making a small case unviable.
In Australia the legal costs have already hit A$5 million ($6.3 million) and are expected to reach A$10 million before the case is resolved.
Wakefield says there are also concerns over how many people sign up. He says many people don't want to risk ruining their relationship with their bank.
"While I wish Andrew Hooker all the best, one element is how many people will want to sign up."
So far more than 18,000 Kiwis have registered but it's uncertain how many have also taken the second step of the process and accepted the costs contract. Hooker believes most will.
In Australia there are 8 million people who could potentially have signed up to join the class action but just 170,000 have, making the total claimable amount A$223 million.
That's a far cry from the billion dollars Fair Play on Fees is claiming it could grab back from the banks here.
Based on the current number of registrations, the New Zealand claim could be around $18 million.
Litigation Funding Services chief executive Michelle Silvers said on Monday she expected the costs of the case to run into the millions and run for at least two to three years.
Wakefield believes even that is too short a timeframe. Wakefield says banks have the resources to keep appealing legal action, dragging out the costs and the timeframe.
He points to the representative action against Feltex. There has already been 10 cases and two appeals but it still hasn't got a date for the hearing."I think they had better be prepared for some significant steps and costs."
Others believe the case is very unlikely to succeed.
Matt Sumpter, a partner at Chapman Tripp, says the case may seem like a populist thing to do but it will be difficult to manufacture liability and prove the banks have done something wrong.
Sumpter says it's a possibility the legal group are just positioning themselves to take advantage of a favourable ruling in Australia.
"I'm deeply sceptical about their ability to get it off the ground. I don't think any of the banks have done anything wrong. There is no suggestion of anything illegal about what the banks have done."
Sumpter says besides the legal case there is also the difficulty of marshalling 10,000-plus claimants.
"Without a medium for managing this style of action it's hard to hold that action together. It just becomes administratively difficult."
He says that any kind of compensation may also end up being just rats and mice stuff for people once the costs have been taken out. "I think it's a bit of PR to test the waters."
Sumpter points to class actions in the US where the claimants receive a small amount of money while the lawyers get rich.
Despite there being a bill before Parliament to make taking class actions easier Sumpter reckons it's not something Kiwis actually want.
"In New Zealand we don't have a litigation culture. A lot of Kiwis will be reluctant to see it happen."
• Auckland barrister Andrew Hooker and Australian law firm Slater & Gordon want to take a $1 billion legal action against New Zealand banks.
• They claim the banks are unfairly charging excessive fees for bounced cheques, unarranged overdrafts, late credit card payments and going over credit card limits.
• The case is based around a principle of contract law which places a limit on the amount a customer can be charged if they default on an obligation.
• More than 18,000 people have registered to join the action since Monday.
• Litigation funders Litigation Funding Services will pay for the upfront costs of the case and charge a 25 per cent success fee if it is won.