Spotify P2P - The Unadvertised Feature

I was recently looking for a way to download the latest version of spotify on my Ubuntu machine (hint: it's not release yet and probably won't be for a while), when I ran across the following thread on the spotify forum:

Spotify P2P uploading and cache

The gist of the thread is that Spotify employs a hybrid download model, of both p2p connections when available and otherwise direct streaming from its servers. However this fact is never advertised to the user. I was quite shocked to discover this, despite having been a user of Spotify for several years. If this was something that was limited to the free version I could understand, however p2p seems to be a part of the paid service too (I haven't yet inspected the traffic myself, however other reports online agree).

While this doesn't affect me personally (not a gamer and uploads don't count to my quota), I can certainly sympathise with those that it does affect. Firstly those who are connected via a service with low data limits with uploads counted, such as on a 3g modem or tethered to their phone. These users often have poor upstream bandwidth, compounding the problem. Secondly, there are gamers, skypers and other latency sensitive users that will have a poor experience and often not know why. It is obvious knowledge to disable your torrent client whilst using these application, however I have never once thought to turn off spotify whilst it is running in the background.

Should applications be required to disclose that they use p2p networking to deliver content? Gaming company ESEA was fined $1 million for hiding a bitcoin miner in their software, in which the company profited from stealing unutilised cpu (or gpu) cycles from end users' computers without disclosure. Should Spotify face similar sanctions for profiting from using excess upstream bandwidth on clients' network connections?

I won't stop using Spotify over this as love it too much and haven't found a comparable service here in Australia. However by including this 'feature' for paying customers without any way to disable or control it, Spotify has given me one large reason to switch should the opportunity arise.