[0cf8612b2e1e]

  If a card swipes in Chicago and seven minutes later swipes in Los Angeles, one of those swipes is fake.

How does this work with online shopping? When I am sitting on the couch and buy from Amazon, where does the address get registered?

Can also imagine an edge case: couple shares an online account, one is traveling and purchases with the saved card details.

[teraflop]

Swiping a card (or inserting, or tapping) is a "card present" transaction. Online shopping, where you type in the card number, is a "card not present" transaction. Retailers and banks can tell the difference.

[rswail]

Also, a Apple/Google/Samsung tap has a different DPAN to the physical card, so it's "card present" but a different card.

[thedebuglife]

They can tell based on transaction metadata. Source: I worked at a cc company

[rootusrootus]

I believe the system distinguishes between card present and card not present.