There is indeed a difference between stealing some product and its fair use, this is where copyright fails in my opinion
An example
In making my little smut films, here are potential problems
I certainly cant put on a music CD in teh background, even if I have bought the CD.
What about the clothing worn? if my jeans have a levis logo visible am I allowed to wear them in my film? what abotu the art on my walls? I have bought it all, but a poster maybe copyrighted, the shoes I am wearing? that the model wears?
what about if there is a call for drinking in the film? can we show the label on the bottle? what about a package of cigerttes
Do I have the right to use the products I have already paid for?
Ale