FBAR and FAICA 條款

Some people or newspaper says tax treaty is $50,000 upper limit. Some newspaper says every account is $10,000 limit. And the fine could be 50% and up to 6 years so far since 2008.
They don't go back to China often. The money will accumulate in bank through direct deposit methods so it is easy to surpass $10,000.
So if the tax treaty starts $10,000, so their retirement account should report monthly/yearly income?
I think it is due to their previous hard work in China and not have any business relationship with US of A. Also it is like pension in USA, why they need to pay 15% tax to USA just because they have Green Card?