Here's a web page about that -> http://en.wikipedia.org/wiki/Grey_market
I'll skip re-writing what is in that article but if you want a warranty you don't want this.
Bob
I purchased my GZ-EX555BU from B&H Photo Video. The only warranty card that came with the camera is for Canada and it makes it very clear that it is for Canada ONLY. Why is this?
I live in the US and bought this from B&H Photo / Video which is a company in NYC.
On another note, I just registered the camera at JVC's site and noticed that my only option was to select the Model GZ-EX555BUS. Note that my Model Number does NOT have the 'S' at the end, only the 'BU'. E.g., the model number on the Camera is GZ-EX555BUS.
Anyone know what is going on here? Many thanks!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic