The following is supposedly a true story. To be included, besides being true, the story is most likely strange, weird, surprising, or funny.
Many folks have written with perfectly plausible explanations about why merchants take my phone number on a credit card charge. What these fail to address, however, is that if I'm perpetrating a fraud in the use of this credit card, I'm not about to give out a correct phone number. They make no effort to validate the phone number before I leave, so what they're doing is collecting the phone numbers of a bunch of honest people.
Now then... Why are they collecting the phone numbers of a bunch of honest people?
I once asked why you are asked for your phone number when using your charge cards. The clerk explained that theives have been caught because they stupidly put down THEIR home phone number, not the phone number of the person who "owned" the card.