I purchased some neodimium magnets in USA (www.kjmagnetics.com) and sent them to a friend in Miami.
When he was returning here I asked if he can bring the magnets instead of mailing them.
Well, long story short, he put them in the baggage and when it was screened by the transport autority, they said it wasn't allowed on cargo. So he took them with them and the same story repeated at the hand baggage inspection.
Luckily my friend had someone at the gate with him, so he handed back the magnets and they are still in USA, if not they would be lost by now...
This happened in Miami International Airport yesterday.