Yes, paranoia.

Makes no difference where the HQ of the OEM is located. Manufacturing will be done in a country even more of a police state than USA (China).

And whatever you the USA based OEM had (tinfoil mode) planned, it could be wiped anyway easily. And as soon as you go on-line, you're free meat for the NSA anyway. Irrespective of where the engineers who designed your memcard had their passport.

Basically what Im saying: Memcard design location is the least of your problems if your you're worried about NSA. We're all screwed anyway. There's nothing that you can do to stop the American empire, if it takes an interest in you. So, just buy the cheapest memory card.