Positive Drug Tests - Ban & Medals Stripped?

Having just looked at the banned athletes (here: http://en.armpower.net/article/en/more-restrictive-drug-testing-in-effect-3040.html) I've had a thought:

Would it not be fair that if someone who tests positive and who is banned for 2 years in the future, that they are also stripped of all wins 2 years prior to the ban. This makes complete sense and is fair not only to the banned athlete but most importantly those who have been cheated (i.e. Pascal Girard who I have seen get silver medal to Rustam Babayev who is a banned athlete, although I'm not sure if he got silver medal within the 2 year time frame I'm suggesting). If this is already in place then great but I'm not aware of it!