Hacking spotify
Spotify is the new "old napster" - everyone who uses it seems to love it. As this Google trends plot shows it is starting to become very popular.
But there is a downside to becoming popular - when you are popular you start to become a target of hackers. This is happening to Spotify now - Spotify is another platform waiting to be explored and exploited. Some notable hacks:
Lastify - this is a rather benign hack - it adds a couple of buttons to the bottom of your spotify client that let you apply Last.fm 'love' and 'ban' to the currently playing track.
Despotify - the open source Spotify client - this is a rather extensive hack. #hack.se has reverse engineeered the Spotify protocols and have built an open source Spotify client (with curses text-mode goodness). The client includes code that decrypts the encrypted music served by Spotify, potentially allowing anyone to not just listen to music, but to download and save it as well. Here's a video of Despotify in action: [youtube=http://www.youtube.com/watch?v=9LUySm2Z8Yk&eurl=http://despotify.se/] Already, Spotify seems to have responded to this hack, according to the Despotify page: "Despotify has been blocked for users using 'free' or 'daypass' accounts. You can still use despotify using 'Premium' accounts.". That seems fair - if you pay for Spotify, you can use whatever client you want.
Geographic hacks - Spotify is only released in certain countries. If you don't live in the UK, Spain, France, Sweden, Norway or Finland you are out of luck - but not really. According to this article in Wired, some users are using a UK-based proxy to allow access to Spotify from places like the USA.
As Spotify gains in popularity, the Spotify engineers are going to be playing a bit of wack-a-mole to keep the hackers at bay in order to keep the Spotify platform stable and performant. So far, they seem to be doing a very good job.