@mangeurdenuage there are migration controls on decks of playing cards, like for poker, because a deck of playing cards can transmit information stenographically through a deliberate order of the cards. This is some "take of your shoes at the airport--forever" nonsense, but for spies and secret communication instead of terrorism.

Now imagine that a future spy can put a microSD card in a little machine, swallow the machine, and then have precisely bioengineered sperm for a while. It wouldn't be 1.5 petabytes due to lots of redundancy, but it's sure beat what a deck of cards can transmit. Airports in 2123:
>take off your shoes
>men, continue onto this line here so that you can get blown by a machine looking for statistical abnormalities in your ejaculate