I've been wondering about something similar recently. What can other countries do to an American webmaster if their laws are being ignored?

If you allow non-US IPs, does that mean you're implicitly accepting that you're serving other countries and thus you're expected to comply with any of their laws? What if you're selling an online service and a foreign user has a US credit card and billing address?

As for the linked topic... Saudi Arabia is a pretty horrible country in many aspects. I'd go one step further and say that American companies shouldn't be doing any business with them. This is a country where women are regarded as second-class citizens. It's fine if some people want to continue with their ultra-traditional gender roles, but you shouldn't impose it on everyone else.