@nvk FUD.

He doesn't specify an attack, he just FUDs rpi platform and giggles and shills his own hardware company.

Could rpi be vulnerable to a TEMPEST style attack? Sure, as nearly all devices are. But you are not going to be targeted by some APT-level organization unless you've got many many many bitcoins that justify the resources that would take.

Interview with the creator of SeedSigner has a good response to this legitimate question many ask.