A Russian researcher at Harvard Medical School was detained at Boston Logan Airport upon entering the U.S. after she failed to declare frog embryo samples on her customs declaration, according to her colleagues. Her visa was subsequently revoked, putting her at risk of deportation, and she was sent to an immigration detention center.
Other countries have been doing this for years. Australia sends people back home all day every day, for failing to declare items. Ever watch those Border Security shows? They are ruthless about it, and most of those episodes are 20 years old.
https://www.sbs.com.au/news/article/a-3-300-fine-and-a-cancelled-visa-traveller-deported-over-undeclared-meat-cheese/3nx0mceka