When does ComputerCraft remove computer entries in the saves folder?

I know that you lose all your program when you pick up an unlabeled turtle and place it again. What I have discovered is that in the saves/computer folder
Computercraft makes a new folder the first time you save a program in a turtle. However, it does not delete that folder when you pick it up.
For example,
You make a turtle and save a program in it and cc will create a folder called "0" and in it is the program you saved.
Then you break the turtle, place it and save a program, it would create another folder called "1".
This bugs me a lot since there is no way you can access the "0" folder anymore and it never gets removed.

So my question is When does cc remove those folders?

If you label the computer/turtle, it will retain its ID number when you break it and put it down again. ComputerCraft never removes those files.

To elaborate on what Lyqyd said, CC never removes files, but when you break a computer, it will have a different ID when placed. You can prevent this from happening by setting a label on the computer (run label set example). Then, when you break the computer, it will have the same ID and keep its files.

to give an idea to why cc doesn't delete the id foldes, what if you accidentally break the computer? if cc deleted the folder when no computer has the id then you would lose all you programs. with the current method you can recover lost programs by copying the data to a new computer (assuming you have access to the host machines filesystem)