I wonder if it is safe to throw away expired cards (credit cards, debit cards, health insurance cards) with name and card/account/ID number as trash. Even if other people have them, will they be able to use these cards in some way that can make me feel worried? How shall I get rid of these expired cards properly, or reuse them in some other ways? Thanks!
Why? Because people will go through your trash, find them and use them. Shredding will make it harder to find the right pieces and glue them together, thus making your account number hidden (or at least not easily accessible).
People who have your account number from going through your trash will probably know other stuff about you from the same source, and can also impersonate to be you, not just use your cards, and that would be a much bigger issue.
I actually wrote an article on this issue on my blog:
If you travel, and some of your card and account numbers are no longer valid, you could carry a dummy wallet with a little bit of cash and these expired cards. If you get mugged, hand over the dummy wallet and don't sweat it.
I don't think you need to worry a whole lot about it.
The worst that could happen is someone could go through your garbage and read your number. But think about this: How many strangers do you hand your card to everyday who could easily read your number? How many times have you typed your credit card number into a website?
If a crook wants to collect credit card numbers, there are much easier ways to get them than going through the garbage. And if your card number does get used, you are not liable for any of it. (Though, admittedly, it could be a hassle, especially if it is a debit card.)
It is often suggested to at least cut the cards up so that they can't be swiped, but once they are expired, they can't be swiped anyway.
The biggest danger is from someone you know stealing the number from your expired card (your child, your "friend", etc.). But someone that close to you would just look through your wallet and grab your current card, rather than dig through the garbage for a card with an incorrect expiration date and invalid security code.
The best thing you can do for security is keep track of your purchases as they happen, then check your statement each month, and promptly dispute any fraudulent charges. Unfortunately, you won't be able to prevent your card number from getting out there. If someone uses your card without permission, it is the bank's or merchant's money they have stolen, not yours.
I do cut up my card before throwing it out, but this is mostly out of habit. I don't think it improves my security much at all.
You should at the very least cut them up before throwing them up. Maybe take a match and melt the plastic numbers and barcode off too.
You should cut up your old cards to protect your identity. Once someone can get one piece of information off you it is likely they have or can get more, thus creating false cards, licences and anything else using your identity without you even knowing it; until you are applying for a loan or something, and they tell you you have a bad credit history. Even though the account on the card is closed they can still use the information on it to make up false cards and accounts in your name.