As much as I want to side with the developers I think they are exposing themselves to legal repercussions and made their situation worse.
Airing dirty laundry is in some jurisdictions a legal offence. Which is exactly why there needs to be agreement spelled out in contracts upfront, that this could happen, and the client would just sign it.
And I am a fan of smart contracts and cryptocurrencies, see my suggestion below:
In the UK, the place where the site in the original link is, it's okay to state facts about a business transaction in public if it's not a malicious falsehood, a violation of contract, or a violation of privacy laws (e.g. sharing emails or recorded calls). But yes, I agree, the issues leading up to this should all be tackled by the contract up front.
That said, there have certainly been situations where builders have gone back to properties and taken back their property (like tiles from walls, joinery, etc.) but I have no idea how that pans out legally as it's outside my wheelhouse.
Far be it from me to hold them up as a beacon of moral value, but in business it’s fair to say you have to pay for service.
It’s not a humiliation, it’s just factual.
You're opening yourself to claims of defamation, tortious interference, disparagement, even coercion, depending on where you are. Not saying the client will win, but they can make it so you'll need to pay lots of legal fees to defend yourself.
It's much smarter to just take the site down without any kind of message, or just something that says "temporarily unavailable". Play dumb with the client, say you don't know why it went down but to fix it but you need to be paid first. Or say it depended on cloud credits that were going to come out of payment, if you don't want it to look like the site went down due to your incompetence.
Making a big public stink might feel good, but it's not a smart business strategy.
My guess is if it was, the client wouldn't agree to it, but who knows (many people just skim over them anyways).
like what? contract says "money for stuff". no money, no stuff.
No stuff is one thing. Different stuff deployed to client's url is quite another.
If the domain is registered with the client named as the formal owner, the client may well be the owner even if they haven't paid for it yet.
Taking the website down entirely or just blanking it out is a very, very different matter than replacing it with a different message; and doubly so when the different message is actively harmful to the customer. Unless the designer's contract with the customer explicitly allowed them to do this, this sort of thing is a slam dunk legal case of either vandalism (using a physical metaphor) or in the UK as in this example, a criminal violation of the Computer Misuse Act.
Not to mention that it's an enormous red flag that will scare away other potential customers for this designer; because it demonstrates that you're very willing to sabotage their operations.
A neutral service suspended message or no response from the server is more defendable if the client goes after you. If you actively communicate on their website, it could be argued you tried to cause reputational harm etc.
Even if you're right, provoking a legal response from a client is more than a lot of creatives and developers can handle, especially if the client is big enough to retain legal or staff a GC.
I suspect that things will turn out fine for this particular developer since the client seems small and the message is mostly innocuous.