Amazon using library cookies?

In the Technology section of the New York Times there is an article called An Icon That Says They’re Watching You that is about an idea to help companies target online ads and still protect your privacy: Mark ads with a special icon that, when clicked, displays what they know about you.

In the comments section there is a person claiming that Amazon used their library information to target products to them. Black helicopter time? Or possibility?

Excerpt of comment: the targeting wasn’t based on my prior purchasing patterns: Amazon pulled it from tracking my recent library borrowing requests.

Last time I looked, the government couldn’t get this info without a subpoena; but renewing my books online apparently allows Amazon to nibble my cookies indiscriminately. Moreover, there’s nothing to stop the govt from getting my library records the roundabout way, through Amazon. And had it not been for those come-ons, I would probably not have noticed or wondered what Amazon was up to.