I'm a bit skeptical that students are a big source of trouble. The vast majority come here, pay universities a lot of money, spend additional money in the local community, get their degrees, and then go home or maybe stay and work in generally high paying jobs, continuing to contribute to the local economy.

All that said, nobody has a "right" to come to the USA to study. It's something we allow, for a lot of good reasons, but there are doubtless a small number of people that we would not want here.

If the contents of their social media would be a crime in the US I would have no issues with denying visa to students.

>Gays are vile and should not be allowed to exist.

Would you be ok with that social media poster being granted entry into the country?

They’d be welcomed with open arms in ~30% of the country. Screening for thought crimes isn’t a slippery slope, it’s a frictionless plane.

Do I think it's the best use of taxpayers' dollars (ie, mine) to screen for objectionable content on social media? No.

Do I trust the government to police opinions? No, especially when there's no accountability and appeals process.

Do I believe the overall benefits that harassment-free international travel brings to this country outweigh the costs of letting in some visitors whose views I disagree with? Yes.

What action would you take re such posters who are citizens in the country?

Yes

You're expected to be truthful in your visa application, and not being truthful is grounds for visa rejection.

That’s different that policing social media tho