They can be real "hard cases" on occasions. Eg, many years ago I had a large box of data CDs shipped to me by NASA (I was a professional astronomer at the time). Even though scientific data is specifically "duty free" they held the box in customs for a month before deigning to tell me that they actually had it, and would only let me have it when when I paid duty on the US$400 that I'd paid NASA to have the CDs duplicated, even though the box was clearly marked "Scientific Data - No commercial value", and that the money I'd paid was for the duplication service, not for the actual CDs I was sent. B*****ds
