I think that Arf could have mentioned that you must never ever allow a waiter in a restaurant to take your card away. The details may be copied or cloned. If this is what has happened to you and you are worried then phone your Card Issuer immediately, explain your worry, and ask for a new card and number. Similarly, never leave a chitty uncompleted otherwise you will find all sorts of gratuities and other things added for which you will be liable. Draw a line through all the empty boxes and ALWAYS FILL IN THE BOX MARKED TOTAL. Also, never leave a car hire firm with an open slip. Even if you have to wait around a bit MAKE SURE THE SLIP IS COMPLETELY FILLED IN BEFORE YOU LEAVE. Otherwise you will find, often huge, amounts added for body damage, missing spare wheel etc for which you cannot escape liability. Hope this helps. If there is anything else worrying you please mention and I will try to help.