Back before Android had gone mainstream, there was an incident where Google removed an app using a feature called Remote Application Removal.
This potentially allows Google to start removing political or anti-authority apps although I'm aware they have so far only used it to remove malware.
Still, I don't trust Google or any other corporation very much and would rather do everything I can to keep them out of my phone.
I already use CyanogenMod 9 (latest nightly 2012-06-21) but since I use the Market/Play it is kind of beside the point.
Is there a way to hack the Market/Play app so that it can't delete apps from the phone without specific authorization from the user?
Alternately, is there a way to set up per-app permissions in CM9 so I can prevent the Market/Play app from deleting anything?
http://android-developers.blogspot.co.uk/2010/06/exercising-our-remote-application.html
http://phandroid.com/2010/06/24/google-can-remotely-remove-apps-from-your-phone/