According to The Digital Reader, Adobe follows the reading habits of users through its e-reader app Digital Editions 4. In addition, the collected data is being redirected to unencrypted Adobe servers.

Nate Hoffelder of The Digital Reader says that traffic using the network tool Wireshark, IP traffic to Adobe servers is being intercepted containing privacy-sensitive data, derived from its e-reader app Digital Editions 4. The forwared data holds records about which e-books are opened and on which page the reader remains. Also metadata collected about the e-book collection and forwarded to the IP address 192.150.16.235, owned by Adobe. Moreover, the e-reader application also scans the contents of the hard disk for the presence of e-books.

Besides collecting user data Hoffelder points out that Digital Editions 4 also doesn't apply any encryption when forwarding the privacy-sensitive data. As a result, the data can be easily intercepted by a third party.

Hoffelder says he has asked Adobe to  respond, but hasn't received and reaction yet.
He further claims that Adobe with his passion for collecting personal data not only violates American privacy legislation, but also the often stricter European privacy laws. According to Hoffelder e-book users should not use Digital Editions software from Adobe for the time being.

Source: Tweakers.net