In the end only kindness matters...

And why are you so concerned with U.S. prisons vs. the Gulag camps? It's different, our prisons are crowded with CRIMINALS only (and unfortunately some people who have been erroneously convicted). Not political dissidents or those who dare to question or oppose government. But, you are right, the USA has the largest prison population. The top three countries: USA, China and Russia. You can see the global statistics here, if interested - http://www.prisonstudies.org/highest-to-lowest/prison-population-total?field_region_taxonomy_tid=All.