The primary mechanism that the investigators are using to find persons collaborating with the terrorists are the credit card records.

That is how they found the flight instructor in Florida, and they have made many arrests off of the transaction records from the credit cards which were used. In other words, the credit card transactions are a paper trail which will allow us to find and prosecute many of those involved in this terrible crime. If the perpetrators of these crimes had completely used cash, there would be no record and none of the accomplices would be caught.

So, use your debit card when you can. Don't use cash (unless you're doing something that you don't want others to know about). My desire especially in the travel industry is that everyone will use a credit card, debit card, or some other trackable mechanism and people paying cash for such will be considered as suspicious. In other words, if you don't want records kept of your comings and goings, then where are you coming and going?

I'm sorry if you think that we have total and complete liberty here. We don't. And to make society safe from terrorists will have to give up even more liberties, at least for a time.

Freedom is a state of mind where you can go about society, buy, sell and travel, know that you are being watched, but also understand that you're living a good enough life that it doesn't matter if someone is watching you. If you have something to hide by paying cash, then you probably need to be looking at the wickedness inside yourself.

Ron Chapman, a very popular DJ formerly of KVIL radio (now with KLUV), used to say that you need to live your life as if you're always on camera, or on the radio, because you probably are. When you least expect it, your conversation is being recorded, or you're being watched. It's just a fact of life.

It's not fun for those who still want to pretend that things done in the shadows are still hidden, but they aren't.

You're being watched and listened to.

Transactions are recorded and kept for both cards.

Two differences. In the U.S., Debit Cards have passwords called PIN (Personal Identification Number), Credit Cards rely on signature matching as the primary mechanism for finding fraud. Ironically, a was speaking to someone who visited Puerto Rico recently ( a network installer for a major company ), and was required to have a PIN number for his Credit Card. Because signatures of Credit Cards are only checked at a few stores I frequent, I'm a strong advocate of PIN numbers, but I want them to be 6-8 digits, not 4.

The other differences is that, with a debit card, the funds are deducted from your account, and you cannot get money if you don't have money in the account, unless you arrange in advance for "overdraft protection", which you pay for with a monthly fee. With a credit card, you are borrowing money at some of the highest interest rates in the country, and must pay the entire balance within 25 days, or pay somewhere between 12% and 25% interest. If you don't remember to make at least some payment each month by the due date, you are charged $29 for your tardiness (that one makes me the most angry of all), which in one case for me a couple of months ago was more than the total balance on my credit card. (I'm really angry about that, too.)

There are some other benefits for credit cards, like additional insurance, purchase protection, credit life option, etc. but in the end you're really paying for all those "features".

But, my point is, if everyone is using debit and credit cards, then the folks using cash are "different". I'm not really concerned about things like whether you use cash for groceries, but I'm really concerned about purchase of big ticket items and use of cash when travelling.