There are hundreds of chances for someone to take your numbers. The fact is - people have to process those cards by hand in the restaurants and stores. It would be ridiculous to single out the person who takes your CC number for food you are ordering, as somehow being dishonest.
You give your card to your waiter and they disappear with it when they go to the register and come back with the reciept - are you going to follow them too?
And why limit it to just the card - they have an electronic record of your card number (it doesn't appear on your receipt, though) so they could just as easily take it there.
If you are that paranoid - don't use credit cards.