I'm outside of my league with this mens rea discussion (didn't look into the details) but obviously the fact that you've performed what amounts to copyright infringement through quoting the phrase you discussed, is quite a different problem from this infringement link.

Let's make it explicit. The Pirate Bay is a common site for piracy, so I went there to get you this link:

* https://thepiratebay.org/torrent/15706308/Captain_America__C... <---- this is the line that starts with an asterisk

What I did was go to the site, then I clicked "top 100" in the header, then I clicked "video | movies" and it was the second link, called "Captain America: Civil War (2016) English BrRip 1080p x264".

Actually you can also find it by googling "Captain America: Civil War (2016) English BrRip 1080p x264" and adding "site:thepiratebay.org" to your query.

Okay, now let's dissect what just happened.

Level1: Firstly, under traditional interpretations of copyright law, the entirety of the present comment (the whole of this comment you're reading) is not infringing on any kind of copyright. I didn't even quote your purposefully short problematic phrase, which you chose because it has been found to be worthy of copyright protection despite its brevity (i.e. similarly protected as a longer work, such as a novel or article). There's nothing copyrighted in this comment, I just authored it out of thin air. I didn't reproduce anything, or include the phrase you held to be protected. I typed it all as a new work.

Level2: Next: I've actually included a link to infringing materials, though. Now am I guilty of some kind of accessory to copyright infringement? My link is actually similar to the article we're discussing. This "level 2" infringement is occurring in the present comment, but if I were to remove the line that starts with an asterisk it would no longer be level 2 infringement. There would no longer be any URL in this comment.

Level3: But, thirdly: what if you remove my link? I've still given you enough information to get to it exactly. The line immediately after the asterisked line tells you exactly how to get there. It just adds 15-45 seconds of inconvenience versus a simple click, and maybe a 20-50% chance that you fail to follow my instructions if you choose to try to do so.

In fact, other than the level-1 line in the sand (which this comment doesn't cross, since I'm not reproducing anything including the short problematic protected phrase you quoted) the rest of the lines in this comment are completely and utterly murky.

Okay, so you've given a tangential example where your comment actually crosses the level-1 line, due to reproducing the phrase "I may ...excellent". Obviously that is an extreme example, but we don't really need to discuss it. Because this present comment (that I'm writing) does not cross that standard. It does, however, cross the level 2 and level 3 standard.

And those lines are murky as hell. There is just nothing there to draw the line at: "THIS is what you're allowed to write; THIS is what you're not."

It has nothing to do with reproducing content - it's about reference to where copyrighted works are available.

I welcome your thoughts as you do know more about this than I do however.