Pirates of the Amazon is/was an interesting experiment that quickly got a cease-and-desist letter from Amazon.com. For a day, however, the site hosted a Firefox extension that assisted the user in pirating works for sale at Amazon. As TorrentFreak put it,
An add-on for the Firefox browser called ‘Pirates of the Amazon’ makes it possible to shop at the Amazon store but leave without paying a dime. Instead, on Amazon product pages the add-on integreates links to ‘free’ copies on The Pirate Bay.
. . .
When the add-on is installed, it integrates a new “download 4 free” button into the Amazon product page when the same article is also available via The Pirate Bay. It works for CDs, DVDs, games, books and basically all products that can be converted to a digital format.
Now that is an interesting mashup. As TorrentFreak noted there are plenty of Greasemonky scripts out there that do much the same thing for Last.FM, IMDB, Rotten Tomatoes, etc. It’s not like it is rocket science to do this with Greasemonkey.
If you’re curious, TorrentFreak is maintaining a backup of the Firefox extension here.