I don't think your analogy makes a lot of sense

Breaking into a house - we have a name for that - it's called "breaking and entering" and "trespass".

However, going along with your analogy, say you're in my house - from my perspective, I would care about what you did.

If you took something that was mine, and denied it to me, I'd be quite annoyed. (I've had a expensive road bike stolen, so yes, I know what it feels like).

However, say you took photographs of everything I owned, to copy my packing style and organisational techniques? Or took them so that you could re-buy everything I have for yourself off Amazon? I probably wouldn't be annoyed, so much as think you odd...

> That hardly makes their copy "not real, for all practical purposes."

Your example of how it's "practically" impacting your life is that if you happen to commit a felony against the person and then analyze their computer explicitly looking for it, you'd happen to find out?

I think that's the very definition of "not a practical difference in my life", given the distinctly low likelihood that series of events would ever happen.

Would you care to try again?

The parent claimed that it was impossible to test for the existence of a copy and that therefore its existence or lack thereof is not relevant. I claimed that it is possible to test for the existence of the copy. I would further claim that there absolutely is a practical difference as far as a renter is concerned, whether or not they test for the existence: The person who copied the rented DVD is very unlikely to rent it again when the want to watch it later. Which I presume they intend to do given that they went to the (admittedly minimal) trouble of copying the movie in the first place. I suppose that in the scenario where it is a lent item, the argument of lost revenue is slightly less strong.