And on distribution any copy left license would do, because it is DRM ruling itself out, as transparency of the code is incompatible with DRM. That's because all DRM accomplishes is a sort of security by obscurity so there can't be generally accepted solutions that are open-source. There's no DRM in Chromium for example. But except for the browser, it's not distribution that's relevant, which is why organizations like the FSF, the EFF and Mozilla are pissed off about W3C standardizing DRM.

I wouldn't hope for any miracles by Apple, when they are single handily responsible for popularizing DRM amongst consumers, along with Trusted Computing. Their whole iTunes / iPhone business is built on top and the rest of the industry followed.

All you'd see in the open source code is a call to that library (just like a call to a binary blob driver from the Linux kernel, for example).

Hulu etc would not be forced to implement their own clients. Someone would develop a general, easily customizable client that Hulu etc would license that supported a plugin system for the DRM components. Hulu etc would license that.

Even if you want to get post-copyright (I certainly do) we don't improve the situation fueling the copyright lobby with technological force multipliers through our own hard work. Keep them honest with copyleft licenses to keep users free of this kind of nonsense.

... and support the GPL compliance efforts of organisations like Software Freedom Conservancy:

https://sfconservancy.org/supporter/

I suspect better content licensing would be best--have a license that forces any distributor to offer media that can be played with FOSS software.

GPLv3 has this clause:

Some countries have adopted laws prohibiting software that enables users to escape from Digital Restrictions Management. DRM is fundamentally incompatible with the purpose of the GPL, which is to protect users' freedom; therefore, the GPL ensures that the software it covers will neither be subject to, nor subject other works to, digital restrictions from which escape is forbidden.

And has a definition corollary:

Complete Corresponding Source Code also includes any encryption or authorization codes necessary to install and/or execute the source code of the work, perhaps modified by you, in the recommended or principal context of use, such that its functioning in all circumstances is identical to that of the work, except as altered by your modifications. It also includes any decryption codes necessary to access or unseal the work's output. Notwithstanding this, a code need not be included in cases where use of the work normally implies the user already has it.

The GPL "stops" apps from using DRM because to use DRM is to violate the license and be liable for copyright infringement.

On OSX specifically, I imagine the Apple had some leaky GPLv3 code somewhere, because they open sourced a lot of Darwin between 2007-2010.

That is, unless they can do cost-benefit. Some markets is just to competitive that you can't waste developer time in order to be afraid of licenses. The game market is very saturated, but there might be places where you can afford to entertain peoples fear.

What if I care about freedom zero? AGPLv3 is incompatible with freedom zero.

I'm not sure you can criticise other people for failing to care about ethical consequences when you are casually prepared to throw away one of the core principles of free software.

They may be misguided, I won't comment on that here. I will just say that my impression is that such an anti-DRM clause exists, and the license that uses it has many detractors.