This always irks me, particularly because I feel uncomfortable questioning protocol. Sometimes I refuse. Sometimes I pay by credit card and they say they need it for confirmation.

In most cases the phone number is the best way to geocode a buyers location. There are a lot of business location analysis going on in the world and geocoding a buyer is a huge part of that.

I usually always give out my phone number (I am a geographer, like I was excited when the census came.) and I have never had calls from the GAP or other stores solicitating anything.

Take off the tinfoil hats and help us geographers!

I had this happen when trying to buy some printer paper. I asked "Why do you need that?" and they said it was so that I could return items without a receipt.

Who, precisely, is going to return printer paper?

They probably have other items at the store that people do return. It's not worth having a different procedure per item.

And besides, maybe you got the wrong size for your printer?

Tell the cashier you don't have a phone. Worst case, you're actually talking on a cellphone at the time and they give you a dirty look.

"I don't have one." is my standard answer when a cashier asks for my email address.

Why just don't answer "No?".

As a German citizen, I find this whole matter very weird. I don't understand the need for the social security number system you have over there.

People just kind of latched onto it because it's a number (supposedly) unique to each individual that most people have memorized.

Names don't work because there are many people with the same name, and besides, they are alphabetic. Phone numbers occasionally transfer to others, as do physical addresses, etc. A Social Security number is always unique to its possessor (theoretically) and, for most adults, is available immediately in memory.

As such, it's become a popular "customer ID", as it were, in a lot of systems. If you assign each individual their own ID, they will forget it and mix it up with other IDs from other places, so an SSN is easy for everyone involved.

The problem is that people assume that an SSN is exclusive knowledge and use it as an authenticator -- when something is a universal identifier that you must write on many documents and give to many people (usually along with all other personal stats like address, phone, names, etc.), it just isn't reasonable at all to think that that can function secretly.

When asked for an SSN, a lot of people don't refuse because they imagine the fight would be fruitless and they'd be denied access to the thing they were trying to get. Some people don't understand much about SSNs or how easy it is to steal identities with them, so they don't mind giving it out. There are certain places where an SSN is legally required (for instance, opening a bank account) and sometimes it's hard to know if you're obligated to give the info or not.

Perhaps it wouldn't be so bad if the SSN were used merely as a user ID and there was an authenticator required in each case, but as it is now, in most cases, you can walk in with an SSN and a few widely published data like name and address, and obtain all kinds of loans and accounts from all kinds of places in the name of the SSN's registered owner, because people assume that only the real owner is able to know the SSN. It's this assumption that is responsible for our difficulties.

Make up a number. Works for me.