IPhone 4: Not killable background application

IOS4 allow application to run in background. Is it possible to have an application running in the background and not killable with开发者_运维知识库out a password?

The simple answer is no.

IOS can always kill your app if it doesn't behave or if memory is needed. Likewise the user can always kill the app if he feels like it.

I don't really understand why you would want this feature anyway?

No. And background tasks are quite limit in their use cases. With exception of location services and audio things, its essential fast app switching / app pausing.