Can Apple delete an app installed via iTunes or the App Store without your permission? I had always thought the answer to this was no. I have an app that was pulled from the iOS App Store (VLC) still on my non-jailbroken phone and thought this was proof that Apple can't remote wipe an app. But I just heard a claim that they can remote wipe apps installed via their app purchase portals if they choose.

Is this true? True for just iOS apps or just App Store apps?
Yes, it's true Apple can remotely delete apps. This is a failsafe in case a nefarious app accidentally makes it past the review process. Not sure about Mac App store, I doubt the ability exists there. It's a different installation/update process.

I don't think it's been done before, and I wouldn't worry about it. It's a good thing. I would want an app that say sniffs my credit card numbers or is actually a trojan horse of some kind to be removed from my iPhone post haste.