Fingerprints? I haven't ever had that happen. Perhaps only certain countries?

People from (all?) visa waiver countries have their fingerprints taken when entering the US, in addition to having to submit an ESTA[0] application before arrival. Last I checked, it still asked for all your social media handles (although you're not required to provide them).

0: https://en.wikipedia.org/wiki/Electronic_System_for_Travel_A...

I've seen it while returning from a trip to Taiwan recently, via JFK. They took fingerprints from non-US passport holders at Customs, I think; they didn't take mine.

I am a US resident alien (green card holder) and I have my fingerprints and picture taken each time I enter the United States.