At least in the US, claiming that you are a nonprofit implies that contributions are tax deductible. Claiming that you are a nonprofit when contributions are not tax deductible might be considered fraudulent.

Not true. There are different classes of nonprofit and they are not all tax deductible. Some nonprofits opt to forgo pursuing that status because it involves a lot of extra administration/filing requirements.

You're responding to a different point than the one I made. It's true that being a "nonprofit" doesn't logically entail that donations will be tax decudtible. But it still implies it to potential donors. The former is a matter of logic, the latter is a matter of psychology. Both are relevant.

Yes, there are multiple classes of nonprofit, not all of which are tax deductible. But it is also true that holding yourself out to the public as a "nonprofit" has the potential to mislead because it may imply to potential donors that contributions would be tax deductible. That is why responsible (or at least well advised) nonprofits disclose which they are, because claiming you're a "nonprofit" in marketing materials, without further explanation, can mislead potential donors.

They are already very much in breach of US law, which they have always been clear about. That aside, they don’t claim that contributions to them are tax deductible.

I would love to see someone try to explain to the IRS why all those purchases of Amazon gift cards and Monero for the transparently illegal organization should be deductible though