For amusement, I often counter that by simply smiling and asking the cashier for their phone number (maybe with a sleezy wink). Their inevitable grin does rather drive home the point that, no, neither of us are giving our number to random unknown strangers.
“Nope.”
Already pisses me off that companies make a profile of me based on credit card numbers. I’ve had this number for decades. I’m sure you could build a complete profile of me based on my cell number, and this is the only “social” site I use. I got off fb in 2008, never even joined the rest (twitter, insta, reddit, et. al.) just because my phone number has been raped out of anyone else who has my name and number in their phone.
I feel sorry for their database because I was a teenager with a bunch of guitar pedals and an ongoing need for 9V batteries. I made up a LOT of phone numbers.