It's not so much how likely it is today. It's just that it's such a random request.

They could ask for a picture of my cat (their right) but why do it?

It's not a US rule (other sites don't ask).
It's no proof (I could mock a passport up).
They can have what they actually need (my bank account so I can pay them/be paid).
I'm pretty sure the UK passport/driver licence is not allowed to be copied and handed over to a third party (ie states 'is the property of HM government).

In fact 123rs waived the passport thing when I offered my business account details.

It just comes cross as someone sticking to a random rule.

Problem is, you send your passport copy to 100 sites and one day things go bad - how do you track down the crook. Saying it hasn't happened to you so far doesn't change things - neither has death.

After an entire batch of uploads was rejected (but a previous one had two, worse, images accepted), I read the Crestock user forum. I wish I had before and saved my time.

I think that the Crestock site is likely to go down if they don't sort out their rejection system. The rejections seem to be arbitrary and then 'composition', etc is added to make it appear to be quality control.

I'm not asking for special pleading for my images but they get accepted on other (bigger) sites. Other people seem to have the same problem and example accepted/rejected images have no discernable differences.

It could be a good site if they were more consistent but I guess they will go the way of the dodgy banks.