iTunes Sync erasing Exchange calendar / contacts

Solution 1:

There is certainly no way built in to Activesync as this covers a broad spectrum of manufacturers using Activesync and does not include vendor-specific options or software policies.

Also, having looked through the iPhone configuration utility, I'm not sure Apple provide a workaround either. Seeing as nowadays from iOS 5 and up a connection to itunes is not required it might be a good idea to disallow it verbally or, if music sync etc is required, possibly get your users to use itunes at work rather than at home. Unfortunately as you have no control over your employees home machines you're a bit stuck for options, there are very few policy options dictating what can and can't be done on itunes it seems.