I'd discovered this about a month ago and have been boycotting Amazon (both .com and .ca) since then - just didn't have time to post this until now.
Here's what the HSUS has to say about this issue:
"Amazon.com's nearly three-year, misguided battle to defend its "right" to sell materials promoting illegal animal fighting has taken a turn against Amazon.com and in favor of animals.
The Game## magazine, one of Amazon.com's co-defendants in The HSUS's lawsuit compelling it to comply with federal law prohibiting the sale of animal fighting materials, has relented and settled the lawsuit. This leaves Amazon.com alone with The Feathered Warrior magazine in challenging federal law so it can continue to support animal fighters.
Fight Back!
Let Amazon.com CEO Jeffrey Bezos know that now is the time for him to abandon his support of animal fighting thugs, comply with federal law, and stop selling animal fighting paraphernalia on Amazon.com!"
IF YOU AGREE WITH HSUS THAT AMAZON IS IN THE WRONG, YOU CAN SIGN THEIR PETITION HERE:
HSUS petition against Amazon.com?
Additionally, here's a discussion about this, with more details, on a dog forum that I found. I happen to agree with not only HSUS' position, but with the comment by Jennj99738 (about 3/4 of the way down the forum page). discussion on dog forum page