This WMA will self-destruct in 5 seconds !

Windows will add a functionality to WMA audio format that will give it a set lifetime. It will be possible to give the sold song a more or less long lifetime. After the set date, or at the end of a subscription, the file will become unreadable.
It seems that they try to sell more and more of these disposable multimedia? We already had the disposable DVDs, games for rent...
This is another means to boost economic growth on a number of consumers that increases very slowly (China isn't really prone to the Web and to cultural products).