When many expats came abroad, the rules were rather lax. They didn't have to file US taxes due to their low incomes.

Later the rules changed, and they had to file taxes. Those who didn't know about the change ended up having to pay a big fine.

Lately, a new requirement was the need to file FBAR forms for every foreign bank accound and security: https://www.irs.gov/Businesses/Small-Businesses-&-Self-Emplo...

Many people didn't know about the new requirement, and they had to pay big fines.

What will be the next new requirement that startles people who don't have any contact with the country? No one knows. That is the risk, the uncertainty that there might be a requirement that you don't even know about...