The software maker states the information is collected for "purposes such as license validation and to facilitate the implementation of different licensing models by publishers". Adobe doesn't offer any apologies for the invasion of privacy and it seems they have no intention to stop collecting your information:
"Adobe Digital Editions allows users to view and manage eBooks and other digital publications across their preferred reading devices—whether they purchase or borrow them. All information collected from the user is collected solely for purposes such as license validation and to facilitate the implementation of different licensing models by publishers. Additionally, this information is solely collected for the eBook currently being read by the user and not for any other eBook in the user’s library or read/available in any other reader. User privacy is very important to Adobe, and all data collection in Adobe Digital Editions is in line with the end user license agreement and the Adobe Privacy Policy.”In response to an article at ARS Technica, an Adobe spokesperson said that they're working on an update but the wording seems to suggest that the update will add encryption rather than remove the data collection feature.