This is hard to believe,
U.S. Courts report that in 2010 it cost $28,284 to keep someone imprisoned in a federal prison for a full year. As you probably know, thanks in large part to idiotic drug laws, the United States has the highest incarceration rate in the world...
per Wikipedia, 743 out of every 100,000 people in the U.S. is incarcerated.
According to a December 2009 report from the U.S. Bureau of Justice Statistics, the total number of inmates in 2008 was 2,424,279 if you include federal/state prisons, local jails, juvenile facilities, jails in Indian Country, military facilities and ICE facilities. Lets presume because of population growth there is a total of 2.5 million people incarcerated today:
2.5 million prisoners X
$28,284 annual cost of imprisonment =
$70.7 Billion Annual Cost of Incarceration in the United States
A guy who hurt no one but himself, why was he put in jail?