RE: Here's my takeEagler, I agree.
Nobody would be stupid enough to massively short SVM and then send an anonymous letter. That would just give themselves away as to who they are.
This is either someone with a relatively small short position, like you said, who wants to make a bit of easy money. Or someone who sees the opportunity to drive it down at a vulnerable time for a company operating in China and pick up some shares cheap.
I doubt that they'll ever find who wrote this. Especially the idiot regulators who don't even know how to wipe their own a$$e$.