"Just curious ... how are these people wanting to scam you this way?"
"Do you still use checks in the USA?
I seem to believe I once saw someone with a check in Belgium ... must have been around 1986 or so.
Anyway ... if you want to buy something of me ... you better pay it cash or in advance by bank transfer.
I never understood the concept of checks ... somebody simply hands you a piece of paper and says: "here ... I promise you this is worth something".
Weird."

The classic scam is that they contact you about the item and arrange a sale. Say your price is $3,000. They send you a cashier's check for $5,000 and ask you to forward the balance on for some other reason. You take the check to your local bank, they say it's good, cash it, you forward the cash on. Then THREE WEEKS LATER, that check gets returned from the issuing bank as being a forged check, your bank pulls their $3000 back out of your account, and you're screwed out of the $2000 plus the merchandise, if any. The merchandise is almost incidental, and you'll hear of this same scam being done with wedding photograhers and the like where it is services to be rendered, rather than goods, that are being sold. The aim is money, not goods.

As to using checks- that may be regional, but is also age-related. I use checks or cash almost exclusively, and have never had a debit card (and I'm 51.) My kids (20's) use debit cards exclusively and seldom if ever use checks. Most other people at local stores are using either debit or credit cards. My kids would never see anyone using checks if not for us. But most local merchants accept checks, and are used to accepting them, so they're not as alien as my kids would imagine.

The value of a piece of paper is basic to the concept of currency. It's all in what you get used to. There are advantanges and disadvantages either way.