Eh, there could be privacy implications. E.g. you see someone in the restaurant whom you know, and you know he is not supposed to be drinking alcohol (for whatever reason: maybe his religion forbids it, maybe there's a medical reason for it such as a prescription drug he's on that really should not be mixed with alcohol, the reason doesn't really matter in this example). You see that he was served a pork chop with a side salad, so you scan through the check numbers and find out that only one order contained a pork chop and a side salad that day, and that order also included a glass of red wine. Congratulations, you have spied on your acquaintance and obtained potential blackmail material on him. What will you do with it? How good or evil a person are you?

And although that's a low-probability scenario, it's also something that could be solved pretty easily, by either using a GUID or at least random numeric IDs with 8 digits.

Isn’t it way easier and way more damaging to just take a photo of him? Receipts aren’t even associated by name unless you’re picking up food.

And before someone comments about the hypothetical religious person eating pork, I was actually thinking of a Mormon acquaintance of mine when I wrote that. Mormons are not supposed to drink alcohol, but pork is perfectly okay. If you were thinking of some other religion that forbids both alcohol and pork, well, that's not what I was thinking about.

I mean I cloud just go over there and see it.

Normally I've not seen any bill that includes the identity of the customer, so it can't be even used as proof.