Ryan Pries, Wei Yu, Xinwen Fu, and Wei Zhao, “A New Replay Attack against Tor Anonymous Communication Network", in Proc. of IEEE International Conference on Communications (ICC) (Best Paper Award of Information and Network Security Symposium), May 2008.
Sill, they need to do a lot more. With the tor network you don't need to control any nodes if you have control of a few routers along the way (Governments). Look up: Wei Yu. Replay Attack still make it easy to know who sent information to who. If it is not End-to-End tor, they know what you send too.
How would the 5 years effect source code? Would this allow people to just use Linux 2.4 or what ever is 5+ years old and sell things without having to show their new source? I would foresee a forking of code coming if ip expired after 5 years.
He has not acquired a fortune; the fortune has acquired him. -- Bion