When creating new references to LogFile or OutputSubscriber objects, the calling script

must maintain a reference to the resulting objects for as long as they intend the subscriber

to remain active. As soon as the script releases the reference (either intentionally, or

due to the variable falling out of scope), the subscriber object becomes eligible for garbage

collection, and will be detached within a short time.

This is to make sure that subscribers don't remain active for an entire PowerShell session

by mistake, if a script author forgets to call Disable-LogFile / Disable-OutputSubscriber,

or if the script crashes before that cleanup code can be called. It is still possible for

such objects to remain active after a script ends, if the script author chooses to place

those variables in the Global scope.