When a Canon Forums user "Kronie" asked the following question:
"Does Canon honor the USA warraties if it's purchased from a non authorised dealer?
If I buy a new 5D MKIII from a non authorized dealer do I have a Canon 12 month warranty or not?"
Canon Forum Moderator "Naomi" responded:
As long as the EOS 5D Mark III was purchased New, In box, you should have the same warranty coverage. To help you out, we've included a link to the Service and Support page on our website for the Canon EOS 5D Mark III camera. Click "Warranty Terms" under "Service & Repair", and you'll find a link to the full camera warranty on this page.
Hope this helps!"
Note: We have no official documentation from Canon substantiating this moderator's claim that Canon will honor warranty repairs for purchases made from non-authorized dealers; however, there are numerous reports that Canon is relatively loose when interpreting its own warranty repair policies.
Update: According to a visitor to the site, the moderator's comment was deleted from the original thread (even though the reply still appears in search queries). Therefore, it's likely safe to assume Canon did not feel the moderator's comments represented its policies correctly. (Thanks Timothy)