I suppose what it comes down to is this: as a designer, when planning a new product, do you (or those who specify the brief) go into it with the intention of only permitting users to do certain things with the product?
For example, when the audio cassette was invented, the ‘recording’ function was an integral feature of most cassette players. The design team didn’t say “we must only allow people to play pre-recorded tapes”; the recording function was important, and indeed it probably fuelled the spread of the technology. It offered customers a benefit that they couldn’t get from, say, a record player. Someone may have considered that ‘illegal copying’ may occur (and of course, later we had the whole “Home Taping Is Killing the Music Industry” campaign), but it presumably wasn’t considered particularly important by the cassette recorder designers or their bosses.
Nowadays, the equivalent thinking in an increasing number of companies (and government agencies) seems to be centred on controlling what the user or consumer can do with the product. Can you imagine if twin-deck DVD recorder/players, together with unencoded DVDs, were the norm? Perhaps it isn’t designers themselves who are driving the change (I don’t remember it ever being expressed as any kind of methodology when I did my design degree), but it must surely be an influential mindset in setting the product specifications or brief in the first place.
Sure, music players and DRM generally are a tired example to use, but they show a clear historical progression from “we’ve designed a product that opens so many doors for the user, so many ways to use it that we haven’t even thought of (think the development of breakbeat and mixtapes)” to “we’ve designed a product that allows the user to do the following thing: 1) Play audio purchased from the following stores, in the following file formats, a limited number of times (if we decide so).”
So, yeah, copyright infringement and user mods of products are different things, but they both relate to how users can interact with designed systems. If you can’t modify a product you own because it’s been designed to be impossible to do so, that product is restricting your behaviour. There are examples of this kind of thinking from other fields—from the layout of cities, to poka-yoke, to speed monitoring technology in cars, to prison architecture.
P.S. As Ringo Starr said in the Simpsons episode “Brush with greatness”, forgive the lateness of my reply