Good article here.
How “Dirty” MP3 Files Are A Back Door Into Cloud DRM
"Here’s how it works. During the buying process a username and transaction ID are known by the online retailers. Before making the song available for download their software embeds into the file either an account name or a transaction number or both. Once downloaded, the file has squirreled away this personal information in a manner where you can’t easily see it, but if someone knows where to look they can. This information doesn’t affect the audio fidelity, but it does permanently attach to the file data which can be used to trace back to the original purchaser which could be used at a later date.
Certain record labels have aspirations to use this hidden data to control future access to music in a return to DRM (digital rights management). The labels yearn to control where you can listen to your music and this could be a backdoor for them to achieve it. When personal libraries are stored in the cloud, it becomes possible to retrieve this personal data and match it to a user identity. If the match is successful the song plays, but if not, access can be blocked through a network DRM system such as the one Lala patented (which is now owned by Apple).
Retailers and record labels should have the right to sell dirty files if they wish, however they should be obligated to disclose their practices in advance. Consumers should have this information so they can make an informed buying decision about whether to support dirty or clean MP3 vendors. If Barnes and Noble printed your name on pages of books you purchase that would be important information to know because it would affect the value of your book. Here the clandestine actions are even more worrisome because it could lead to a future lockdown of purchases. If the labels have plans to require cloud vendors to use this information in the future, they should disclose that as well."
So, it's like putting up your personal information on the internet without your knowledge or consent. Hmm.. it's not "like" that. It is that. Utter fucking bullshit.
(ahem... the irony is not lost on me... ;)
Another reason to download your music for free. If you like it, buy the record, buy the t-shirt, go to a show. Most artists make almost nothing from album sales and almost everything from t-shirts and shows. This is just another way for corporations to control what you can and can not do with your stuff. Moreover, this is spyware, a virus, and will expose you and your personal information without your consent.
"Napster, Amazon and UK based 7digital are selling clean MP3 files... Other retailers such as Apple and Walmart have succumbed to label pressure to embed personal info."
1 year ago