Even if, you leave the original in a pristine state, the fact that multiple copies are available and can be used (for good or nefarious purpose), dilutes or erodes the value of the original.

And this is true for both digital content or something as intangible as an identity.

So I am not really convinced by the simple argument that since the original still exists untouched, everything is fine. Yes, this is surely convenient and better for the original author/owner/creator, but not enough to say nothing harmful happened.

There are multiple copies of the Mona Lisa. Many, many millions of reproductions. Is the value of the original Mona Lisa diminished because of it?

Time and labor are resources that get used up too.

You're paying for the creator's time and labor. Taking the product of that time and labor without compensation is theft.

That is the common rebuttal, but if someone illegally downloads a film he or she never intended to purchase or rent anyway, then that argument does not hold. Even if the choice is between buying something legally and downloading it for free illegally, that word does not apply.

Loss of income does not equal theft.

Whether you have then been wronged or not is another discussion with valid arguments on both sides.

If you did not want "to purchase or rent " legally why is it ok to do it illegally? Is it that you did not purchase or rent it because you knew that you could simply steal it?

I am neither condemning nor condoning illegal downloading when you had no intention of paying for it — merely stating that it is not theft; the differences are just too great due to the nature of digital content (i.e., being able to effortlessly copy an item without incurring more than trivial costs).

Why not call it copyright infringement if you want a more neutral term?