As long as they don’t make me sew an ID card onto to my forehead I can live with it.
I use the Tijuana border crossing and get car pictured going in, coming back: card ID automatically machine scanned, car x-rayed, car is dog sniffed for drugs while waiting in line, car photoed again, question by border patrol agent after handing them ID card, usually just a quick trunk open inspection, did you buy anything question, what was your purpose in Mexico question and destination in the US now.
Any suspicions and you get sent to Secondary where they can disassemble your vehicle and detain you if they feel like it.
A long time ago, it only use to be, “What is your citizenship? and Are you bringing in any fruit from Mexico?” That was it.
Scanners at airports are the real personal violation.
It’s a mini-passport ID card only good for re-entry from Mexico and Canada by foot or vehicle, can’t fly with it, you need a full passport for flying or extended stays. You go through the same steps when applying for a card like a full passport but it costs like only $50-$75 the first time around. Both card and book have chips.