Since I couldn’t reply to the guy who didn’t know we “criminalized cash”... $16,000 specifically is an issue because crossing the border with any amount of cash over $10k has to be disclosed. If you don’t, it’s considered like contraband.

No problem if you disclose and explain what it’s for, and in some cases can explain where it came from.

This is a basic money laundering protection policy almost every country I’ve gone through has similar.