Don't look at it that way...
Fighting Tur is going to be cheaper than fighting Viacom. He doesn't have Viacom's deep pockets.
But Tur does bring up an interesting point.
Does Google/YouTube have a way to limit or block infringing content?
The answer is maybe.
Sure they can tag a file when its uploaded, such that any attempts to reload the same clip will cause it to be rejected. And they can ban a person from uploading content if they are found to be uploading copyright infringing material.
Yet, they can't stop someone from taking a "clean" copy and uploading it, or manually removing their "digital watermark".
The point is that they could have made a reasonable effort to try and stop abuses. Even if its not 100% effective, it would have shown that they were trying to comply with the law, rather than ignore it.
IMHO Tur and Viacom's cases do have merit.