Which is the same as "there are still old school HN technologists who refuse to use Facebook. And the privacy/security is absolutely a major problem."
It's not the same at all. At first glance it might feel the same, but the structural questions are different. The fact that the Facebook does have privacy problems does not show that Atlantic salmon does actually have parasites problems in the same way that pacific salmon does.
Argument by analogy is not good argumentation.
In the USA fish for sushi is suggested by the FDA (and required by local law in some places: New York city comes to mind) to be frozen to -31F for 15 hours (or -4F for seven days), specifically to kill parasites. Given that virtually all salmon in the US has been frozen, I wouldn't worry about parasites in salmon sushi here.