Jeremy Zawodny: Lame Programmers and Credit-Card Numbers:

Some programmers are so lame that they haven't figured out

how to strip spaces and dashes from input. Really.

I once had the "pleasure" of writing an interface to a credit-card gateway. In order to be allowed to hook up to the live system, the interface had to pass a series of tests.

One of the tests: the interface was _required_ to reject card numbers containing spaces, hyphens, indeed anything but numbers.

I phoned support to question this requirement, and was flatly told that there would be no negotiation entered into. Their reasoning was that they had some kind of fiduciary responsibility to make sure that whatever got typed in as the card number got sent verbatim to the bank. So I shrugged, and did what I was told.

This is stupid, of course. Most people read and write credit-card numbers as, say, four groups of four digits (or whatever the groupings are for Amex, JCB or Diners, I don't have examples handy). Forcing people to mash numbers together without grouping them makes it more likely that they'll enter the wrong number, not less.