We use DO as our provider, and we offer trials in our product offering, so if they attach a prepaid card to _our_ service (which people do, all the time), we're out that money, but it's $5 for us, so we eat it.
If you haven't preauthorized, you aren't guaranteed payment. That's why these services also have usage limits, of course--AWS doesn't want me to rack up a million dollar bill without seeing a past payment history that would indicate I can actually afford that.
Then if they don't want that, don't be bill-after or companies like Privacy will just engineer around that prepaid card limitation.
With physical goods, there is always the possibility that the merchant could compel you to return the physical good, but with cloud computing, that's nearly impossible.
https://support.privacy.com/hc/en-us/articles/4414521565719-...
> On December 31, 2021, we will close all Visa Privacy Cards that have not been updated. In order to continue using Privacy.com without interruption, we need you to complete a few simple steps. Visit our FAQs to learn more.
Via the popup transition tool when logging in.
Sad they couldn't keep existing cards open till they expire, but just recently their card expiration dates jumped to lasting till 2027 so I see why.