I know of at least one site in the US that does the same. B&H, a venerable camera & electronics store in NYC, shuts down their shopping site every Saturday (http://www.bhphotovideo.com/).
Which is weird, but I guess I don't know much about the finer points of the Law. Would a religious Jew have to lock down a windmill before the start of the sabbath? Or does it only matter for matters of trade? Technically, wouldn't they have to lock their Paypal account as well, as well as traditional bank accounts?
No, they are not required to shut down their site by the letter of the law. However accepting money on the sabbath is not in keeping with the spirit of the sabbath, so I fully understand why they shut down.
A human is not allowed to work on the sabbath, but your machines can, as long as they run automatically.
Interestingly work animals are also required to be given the day off.
The main thing that is not in the spirit of the sabbath is accepting payments, even if by the letter of the law it's allowed.
For example, even though you could leave a physical shop open and unstaffed, and let people (non-jews) buy using the honor system, it's not the right thing to do.
However, leaving the shop open, so people can take things without money, and then they settle later is OK.
Oh yeah, I totally grok that. If you shop at their storefront location, you can see that they are staffed almost entirely by Hasidim. I was just pointing out an instance of a US-based e-commerce website that also closes for the sabbath.
