Under the law it would different, none of your examples are protected classes, discrimination in employment is only illegal if the targeted/excluded group is a

Under the law it would different, none of your examples are protected classes, discrimination in employment is only illegal if the targeted/excluded group is a protected class, those being: men and women on the basis of sex; any group which shares a common race, religion, color, or national origin; people over 40; and people with physical or mental handicaps. The company I work for, for example, does not hire smokers (and makes this clear during hiring and makes the specifics part of our contracts), and this is perfectly legal. But it would be illegal to not hire anyone based on being in, or not being in, one of those specific protected classes. Now, if they were being used as proxies for those classes, then yes it would be illegal, but it would be up to a court to determine if that was the case. If I ran a company that made action movies "Must love action movies" being a basis for my hiring decisions is obviously not intended as a proxy for a protected class and would be legal. If my company makes printer paper, then I'm on shaky legal ground. That being said, I'm not sure if there are actually laws making it illegal to publish discriminatory job ads for someone, but Facebook assisting in illegal and discriminatory actions is an issue regardless of if their part is specifically illegal or not.