Good answer by bertieb. Let me just offer my take on some supplementary refinement on the gray area.
We don't support Warez or stealing services, but it also isn't our job to police the Internet. So where's the line between the two?
A few examples:
- With DRM, the person could have legitimate rights to personal use of something they purchased, and we can't parse each contract or TOS.
- If you're allowed to freely download something but it comes with TOS, it wouldn't be our job to figure out and enforce the TOS (but see Hackintosh discussion below).
- Some web content has no stated or obvious restrictions on downloading; it is simply a technical hurdle. We support that.
- If a web site has protections and controls over what proprietary content you can download and how, we generally don't tell people how to cheat the provisions. People make their living developing content and have the right to control and limit your access to it.
I think what it comes down to is this: we won't help you defeat controls to acquire something, or knowingly support warez, but it you already own it, either because you purchased it or it was freely available, we'll extend the benefit of the doubt in helping you use it.
It isn't our job to police how you obtained it, but if we're familiar with the software and know that your copy must be warez, we won't knowingly aid and abet piracy. Or if you were dumb enough to describe that you have a pirated copy, we now know and shouldn't support it (don't ask, don't tell).
With Hackintosh, there's the argument that it is unsupported, so out-of-scope on that basis (it's not designed or tested to work on other hardware, so there isn't a "right way" to make it work; that comes more under the umbrella of development).
So my take on the question of downloading from YouTube: it depends. If content can be downloaded with readily available tools like browser extensions, and there is nothing but a TOS notice saying not to, it's not our job to enforce the TOS. But I would say that we shouldn't provide technical support to bypass intentional provisions put in place to prevent downloading. In my book, that would be piracy.