And yes, that distinction does matter. When somebody infringes, nothing is lost. The opportunity for a sale still exists, the property is still owned by those who own it, and so forth.
For there to be theft, there needs to be some meaningful loss on the part of the person claiming theft.
We have the word infringe for this case, because nothing is actually lost. What actually happens is somebody does something they aren't supposed to do, which is a different thing, and not inclusive enough to be theft.
Now, citing theft is nice, because it's easy, clear and very negative. People identify with theft easily, and that's potent. Advocacy centered on theft is understandable, but it does as much harm as it does good.
Why?
Because theft and the direct equating to lost sales does not reflect the realities in play. Where we make law on that basis, we tend to get crappy law that is ineffective.
People see stuff like $150K / infringing act and or proposed jail time, and it's laughable compared to something like rape or real theft that carries far lighter penalties, and that actually is theft as opposed to infringement.
I submit we really can't make progress on this without also entertaining a rational discussion, and tossing theft in here really isn't rational. It's too coarse and inaccurate.
Infringement is wrong. And it's a harder discussion, but a necessary one. Until average people get it, and understand all of it, we will continue to see a big disconnect in both the discussion and law, leaving the door open for more piracy and fewer solutions that can compete with it, etc...