Maybe. A lot of freelancers and agencies have amateur or no contracts.

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.

if the company is big enough to have legal staff, said staff would probably have advised them to pay in the first place.

You would think so! :)

But this is very obviously not "no stuff". This is "different stuff".

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.

it's not the client's website yet, they haven't paid for it!

> no money, no stuff.

No stuff is one thing. Different stuff deployed to client's url is quite another.

It's not the client's url if they didn't pay for it.

In the case of a URL it might be.

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.

Then the client can move the DNS for the domain and use a server they control and have paid for.