“To facilitate this vetting, all applicants for F, M and J non-immigrant visas will be asked to adjust the privacy settings on all their social media profiles to ‘public’”, the official said.
This isn't theoretical. Both China and India, the two countries that supply the most students to the US, prohibit marriage equality. Both have extensive discrimination throughout their societies, both at the government and cultural levels.
Here in America, you can't put someone on trial for a crime they haven't committed. Even if you think they're from a suspicious country. That's called racial profiling, and it's forbidden by civil rights laws for a reason; nobody should have to tolerate the indignation of their peer's stupidity.
Actually in the US you can - it's why there's stories of innocent men and women being released from jail after other evidence proves their innocence (eg: DNA).