But still, there are a lot of scammers that are much brighter and could win the case if and only if the evidences are purely alone by one person and without any other supporting claims.
or they could've hidden themselves well which makes getting back the money a lot difficult. Same thing happened in bitconnect which I think is the motivation in suing the third parties (e.g. youtube). There's also the possibility that they can't pay their victims back because they already spent or laundered it. So yeah that's another thing for op to consider, they could win the case but not get their money back or get compensated enough.
In any case it's better to consult with a lawyer first.
The only thing that bugs me is that about provision or rule on crypto crimes. What if certain country doesnt have that? So how certain guilty can be convicted if he knows that the country his in dont have specifics yet.
I think anything with monetary value should be fine