How many of us when reading an apparently valid link in an email would bother to check whether the link is actually valid or whether instead it takes you to a malicious site.
Pretty much you bring in your check, show the clerk a valid ID, then on this little machine, I believe is also used for swiping credit and debit cards, the customer inputs their social security number.
Even reputable news sites often only check that the e-mail address you have given is valid, but make no effort at all to verify that you are who you claim to be online.