Short answer - MOST videos are ILLEGAL to sell out of the country or "trading" area. You can normally sell DVDs with in the licened area - in Canada it normally okay to sell in US/CANADA and maybe Mexico....
However it REALLY depends on the licence of the DVD. Many are Licenced to be sold in certain areas or countries. This is not the same as if you go overseas or to another country out of this "trading" area and by something and bring it back with you.....
On the BACK of one of my DVD (Space Jam) it states...
Quote
WARNING: For sale or rental for private home use in the USA and Canada only. Federal law provides severe civil and criminal penalties for the authorized reproduction, distribution or exhibition of copyrited motion pitures, video tapes or video discs.
(Copywrite 1997 - Warner Home Video)
THUS if you sell and ship it outside of the USA or Canada - it volates there copywrite and/or licence and is subject to a law suit from the distrubution company/manufacture. (PS the boarder customs officers don't care - but would help if reqested....) It would be UP to the Distributor to find out, investigate and file charges....
This ALSO may apply if you IMPORT a item that is NOT licenced for your country....
NOT all DVD are like this. It depends on HOW the content was licenced.
Good Luck