Geo-encryption, using the location of the recipient as part of the decoding mechanism. Troubleshooting this is going to be like tuning an old TV with rabbit ears.

"Left...left...back...ok, we've got the first sentence...crap! The GPS signal dropped out again. Lift your arms...just one...turn to the right a bit....right arm up halfway...yeah, that's it, leave your fist balled up like that. Got it, decoded!
Aw, it's just more Herbalife spam."

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