$800,000 donated to help Memories Pizza recover from gamergate like harassment

In general, everyone has the right to discriminate. A store is not required to accept the trade of drunks, vandals, etc. The exception, and it's a major one, is that discrimination is not permitted on the basis of race, national origin, etc. This extends to proxies, so a rule which requires customers to take off their hats may not include religious headgear, unless there is a bona fide reason.

vishaldpatel? In most parts of the US, desire to discriminate is not a protected class, so it would be fine for anyone to decline trade towards a member of the KKK. California, however, has a very broad civil rights protection law. In 1988, four men were refused services and ejected from Alpine Village, a German restaurant, for wearing a Nazi pin. The California Supreme Court held that was a violation of the Unruh Civil Rights Act.

In California it likely illegal to decline trade to a KKK-affiliated organization on the basis of their political beliefs. I am no lawyer, but my guess is that if there's a reasonable belief that employees will be subject to a harassing environment, such as being present to cater at an event which promotes racial violence, then that's an acceptable reason for a business to not provide services, even in California.

The last situation - a Muslim forced to serve pork despite religious preferences - is ridiculous. There's nothing in anti-discrimination law which makes that requirement. Any law which required a Muslim-owning restaurant to sell pork products which didn't require vegetarian restaurants from doing the same would be discrimination on the basis of religion. Any law which did not have a bona fide justification for the law to prevent religious exceptions would also be discrimination on the basis of religion. And I'm hard-pressed to think of any bona fide reason.

(As an aside, my own great-grandfather refused to sell cigarettes in his store due to religious beliefs that they were an inappropriate vice for a Christian to support. What anti-discrimination law would force him to sell tobacco?)

A better example would have been if a restaurant owner decided to start selling pork products and anti-pork waitstaff objected, on religious grounds. The US accepts bona fide occupational qualifications (BFOQ) for discrimination. For example, a Playboy Club has a dominate service of providing sex appeal to is customers, so is allowed to discriminate on the basis of sex and beauty. Similarly, an employee at an adult store may not sue for sexual harassment due to the workplace presence of pornographic material, even though that the same materials at another workplace may judged discriminatory.

The owner of a pork BBQ restaurant may fire employees who decline to handle pork product, even if there are religious reasons for doing so. Note that the bar for a BFOQ is pretty high. Hooters is not able to use the Playboy Club exception because it is in the primary business of serving of food and beverages to customers, not serving sex appeal.

BTW, vishaldpatel? The fact that a Muslim restaurant owners would eat the food they themselves serve is irrelevant. A lactose intolerant cheese shop owner can still sell cheese even if unable to eat the cheese. The owner of a pet store can sell meat-based dog food even if the owner is a vegetarian for religious reasons.