I was just playing some Bowie off google play music on my PC and became curious as to how they have stopped illegal downloading. The All Access feature of google play means you can listen to any music on their servers for a fixed fee a month so I figured they must have a mechanism to stop users downloading anything they're streaming.
I opened up the network log and opened the URL of the audio stream in another tab. It opened fine and showed the MP3 play buttons as expected but the play button does nothing. I understand they will probably be using some kind of cookie method to stop hotlinking but that doesn't mean you can't download it shortly after you've clicked play in the play music client. Its been racking my mind for a while now and I can't think how they might have done it. They seemingly just use the new HTML5 features to play all audio.
Does anyone have any insight into how the genius' at google have done this?