Professor Austin said some countries, including the UK, had a "small claims" system for copyright cases such as this.
He said the system helps make sure copyright law is not just for the big firms and is something New Zealand should be looking at, but that without international co-operation, even this wouldn't help in the cross-border cases.
The case of the stolen baby photos perfectly illustrated the issue, Professor Austin said.
He said whoever takes a photo is the author of that image and under most circumstances will also be the owner of its copyright.
"In the early days of the internet there was an idea that anything you uploaded freely that you didn't password protect, there was an implied licence for people to use that. But that never extended to the use in another person's business context or in another advertising-supported website.
"So just because you want your Instagram followers to see it, doesn't mean it's freely available for businesses to use in the sale of their products."
Professor Austin said many countries' copyright laws have got something called a "notice and take down" procedure, where if you're the copyright owner and you see something on a website, you can send a notice and often countries' laws oblige the poster to take the thing down as quickly as possible.
"China, for example, has actually got this law but it seems like [Mrs Paewai] had the experience where the thing keeps on going back up again. So it illustrates how you can have very good law on the books that sometimes is practically difficult to enforce."
Mrs Paewai had contacted the seller on AliExpress and asked them to take the photos down, but the images have since popped up many more times on the site.
This comes down to the carrot and stick, Professor Austin said - how big the incentive is to take down the photo and keep it down.
"The reason why businesses comply with those notices is that if they have a policy of taking things down when told there's an infringement of copyright then it's harder to sue them.
"That's the carrot. That carrot can be fairly meaningless if they know that a mum in New Zealand is not going to be filing copyright infringement proceedings against a foreign website."
Professor Austin said posting something on a social media site can make things more complicated, however, and so before posting something people should really check what the website terms of use say about copyright ownership.
The website Mrs Paewai's photos appeared on, AliExpress, is owned by Chinese e-commerce giant Alibaba Group and offers products to international buyers - often from small Chinese businesses.
An Alibaba spokesperson yesterday told the Herald that as a matter of policy on the AliExpress website, listings for any products with unauthorised use of pictures are prohibited.
"Our team will help prevent the listings of any items that go against our policies upon notification. We will take steps to remove the infringing listings and the respective sellers will be subject to our progressive disciplinary measures.
"We can take down those specific photos upon notification, but need the mums to log in their take down requests first through AliProtect because they need to show the original photos to prove they are the copyright owners of the images - that is also being fair to the sellers. Once their requests are accepted, we will work on taking down the photos immediately."
AliProtect is the company's online infringement reporting system, where people can file a take down request on any product listings that are involved in unauthorised use of photos.
