An Oscar Nominated director cannot attend the ceremony[1]. Ironically he's been persecuted by his own government, but he's unfortunately not a Christian so Trump doesn't care. People with green cards aren't being allowed to board US flights[2].

Also look at the countries he's selected- Iran, which is not host to ISIS or Al-Qaeda, and who have not had any of it's citizens ever carry out an attack in the US. The main crime of Iran seems to be that it's not a US ally. If this is allowed to become a precedent, if say the Indian government does something to upset the US, what's to stop Trump from banning visas from them too?

[1]-http://www.independent.co.uk/arts-entertainment/films/news/d...

[2]-http://www.independent.co.uk/news/world/americas/donald-trum...