Someone seriously needs to be taken to task for filing a false DMCA. DMCA is just another term for SLAPP these days. If anyone is a lawyer, they could still be despite retracting the case?
YouTube’s TOS would be the most critical place to begin in terms of evaluating legal options. To file a “DMCA” (not really DMCA but YT’s proprietary version of it) claimants generally have to create an account and agree to the TOS. So it may bind both parties (the YTer and the abusive DMCA claimant). That might limit legal options for anti-SLAPP, tortious interference, etc.
But without either significant legal expertise or someone finding some particularly relevant case law, it seems like a nuanced enough domain that no one’s lay “legal” opinion would be particularly illuminating.
So even if the case is clearly being used to strategicly silence you, it'll probably still work (from plaintiff's POV). Same for DMCA.
Of course, one of the other issues is there's no federal Anti-SLAPP statute, and circuits are split as to whether or not state Anti-SLAPP applies to federal lawsuits, so if someone can diversity jurisdiction you into a federal SLAPP lawsuit, you're kind of stuck.
You'd better have a slam-dunk of a case if you're going to easily find contingency lawyers. The worst thing you can be is just "too rich" to qualify for pro bono representation... but even then, you still need a slam-dunk case.
I am currently in the process of suing somebody (plaintiff), for the first time in my many decades, and am a semi-retired electrician of average savings... and it is expensive and probably not worth my time but (in theory) hopefully worth it on principle.
So ready for this to be over with; the lawyers will certainly get their$.
Sounds like a CivPro hypothetical exam question that would give law students nightmares.
And then fine plaintiffs (and pay the defendants) that lose a summary dismissal, because if your case can be thrown out before trial, it was a shit case that should have never been filed in the first place.