I finally got around to reading the court case. I'm not so sure if I agree with your assessment about "all circumventing activity". I don't think this has anything directly to do with StreamFab. According to the AACS website, they only deal with security of optical products. All the programs that are listed as conducting circumventing activity are all those that we usually associate with DVDFab DVD and Blu-ray products. DVDFab Streaming products, such as StreamFab and MusicFab, use a different copyright protection not represented by AACS (Widevine, PlayReady, Fairplay). Of course, if the injunction closes down domain names, websites, distributors, and financial resources, that will surely have a major effect on StreamFab and MusicFab.
I'm going to have to reread it again, but I can't understand why Tao ever responded back to the preliminary injunction in the first place. They are sitting pretty in China where most of the world's laws don't apply. As far as I know, email is not a valid method of serving papers. I think the magistrate just closed his eyes to those facts, and it should have gone through the Hague.
Cats4U
They're enjoined from trafficking anything that circumvents AACS technology "including but not limited to the DVDFab Software" - but since AACSLA does claim it "facilitates the ability to offer exciting, new, flexible entertainment experiences for consumers to enjoy in stand-alone,
 networked home and portable device environments," it sounds like it might cover streaming video and not just DVD technology. The injunction enjoins them from further use of any domain names and website where "circumventing activities take place." StreamFab may be advertised "since 2019" but it's advertised on, and can be downloaded from, the DVDFab site, so it may fall under that umbrella. It also enjoins "any banks, savings and loan associations, merchant account providers, payment processors and providers, credit card associations, or other financial institutions which receive or process payments or hold assets on Defendants’ behalf" to stop providing services to them.
I also would've not responded after the court awarded AACSLA that preliminary injunction in March of 2014 by default since Feng Tao et al didn't appear, but his counsel filed a motion to amend it on April Fools' Day - which is pretty ironic, if nothing else. You can motion a lawsuit to the moon and back to delay it, but by April 2016 AACSLA was demanding that Feng Tao et al be found in contempt of the preliminary injunction and demanding a second one be issued, which it was. Feng Tao filed what's known as an
 interlocutory appeal in the Second Circuit Court, which is an appeal of a non-final order that's been issued while litigation is ongoing, and actually won that one in 2017. It's only after that, in 2018, when they were probably giddy that they'd won 
something, that Feng Tao's counsel filed the motion to dismiss AACSLA's complaint based on insufficient service of process (which was doomed to fail since four years of legal motions demonstrated that Feng Tao certainly had knowledge that he'd been served), and the next day AACSLA filed for a default judgment. 11 months later Feng Tao's motion to dismiss due to insufficient service was denied, and an order of default judgment against Feng Tao et al was entered.
Then in 2019, Feng Tao et al filed an opposition brief and there were further back and forth motions about that. They also argued insufficient service for a second time, this time for AACSLA's injunction order, claiming service had to be done according to The Hague Convention - the idea here was if AACSLA couldn't serve Feng Tao personally in China, then any injunction order would essentially be unenforceable (remember that AACSLA claimed they could never come up with a physical address for him, which is why he was originally served by email.)
The problem is, their counsel couldn't cite any case law - and worse, the brief quoted from a statute that specifically states that an order granting an injunction binds those
 “who receive actual notice of it by personal service or otherwise" - since Feng Tao was represented by counsel and had obviously received actual notice of other filings through the ECF (Electronic Case Filing) system, claiming he hadn't received those notices 4 years into a lawsuit was a non-starter, so oops. Feng Tao et al’s request to require service of the plaintiff's permanent injunction in accordance with The Hague Convention was denied.
Email is actually considered a valid method of service for courts here in the US, as long as the plaintiff can establish that the e-mail is likely to reach the defendant, and can demonstrate due diligence to obtain a physical address so that more traditional forms of service can be carried out. AACSLA hired private investigators to suss out Fen Tao's address, apparently to no avail, while Feng Tao refuted this, claiming it was easy to find his physical location.
BUT WAIT THERE'S MORE - Feng Tao tried insufficient service 
yet again in July 2023, but as he'd earlier admitted to having received the summons and complaint by email in February 2014, and a lawyer from another firm contacted him that same month offering its legal services because he was being sued in the US, and because he'd also extensively participated in pretrial motions, it was dismissed. Courts usually consider that knowledge of a suit combined with pretrial activity on the defendant's part is essentially a waiver of any insufficient service claims by the defense, especially where any delay due to motions of insufficient service has been to the detriment of the plaintiff’s case. You can't actively participate in your own defense before the trial even starts and then several years into that same trial claim you had no idea you were being sued because you weren't properly served.