Disclaimer: I'm an Australian in the US on a work visa.
I'd consider it "not ridiculous" if the vetting was limited to ensuring:
- That my visa application is valid: If I'm coming to work, I'm doing it for a real job and I really do have all the necessary qualifications and my travel plans match my intent.
- That I'm likely to leave the US. I think it's fine to ask whether I have ties to my home country or to the US and whether I've broken the terms of another visa.
- That I'm not already a criminal. It'd be fine to be asked for a police report.
I consider the following ridiculous:
- Anything related to potential future terrorism. If I wanted to enter the US to kill people, why on earth would I get a visa when I could just cross the border illegally or use a fake passport?
- Compelling disclosure of any information a citizen could deny a police officer who lacked a warrant.
Then again, I understand that the US considers visas to be a privilege and I respect its choice to deny them to whoever it wishes. If it decides I'm not good enough, I'm more than happy to take my economic output elsewhere (and I will if they ever ask for details regarding my online presence).