The United States has about five percent of the world’s population and houses around 25 percent of its prisoners. In large part, that’s the result of the “war on drugs” and long mandatory minimum sentences, but it also reflects America’s tendency to criminalize acts that other countries view as civil violations.

In 2010, The Economist highlighted a case in which four Americans were arrested for importing lobster tails in plastic bags rather than in cardboard boxes. That violated a Honduran law which that country no longer enforces, but because it’s still on the books there its enforced here. “The lobstermen had no idea they were breaking the law. Yet three of them got eight years apiece.” When the article was published 10 years later, two of them were still behind bars.

A UN report noted that Alabama officials had arrested dozens of people who were too poor to repair septic systems that violated state health laws. In one case, authorities took steps to arrest a 27-year-old single mother living in a mobile home with her autistic child for the same “crime.” Replacing the system would have cost more than her $12,000 annual income, according to the report.

As The Economist put it:

America imprisons people for technical violations of immigration laws, environmental standards and arcane business rules. So many federal rules carry criminal penalties that experts struggle to count them. Many are incomprehensible. Few are ever repealed, though the Supreme Court… pared back a law against depriving the public of “the intangible right of honest services”, which prosecutors loved because they could use it against almost anyone. Still, they have plenty of other weapons. By counting each e-mail sent by a white-collar wrongdoer as a separate case of wire fraud, prosecutors can threaten him with a gargantuan sentence unless he confesses, or informs on his boss. The potential for injustice is obvious.

About 10 percent of America’s prisoners are housed in the federal corrections system. Last week, the Justice Department’s Office of the Inspector General released its annual review of DOJ operations. And couched in typically cautious bureaucratic language, the report details a growing crisis within the federal prison system that threatens to undermine the DOJ’s other vital functions, including the enforcement of civil rights legislation, counter-terrorism and crime-fighting.

According to the report:

The Department of Justice (Department) is facing two interrelated crises in the federal prison system. The first is the continually increasing cost of incarceration, which, due to the current budget environment, is already having an impact on the Department’s other law enforcement priorities. The second is the safety and security of the federal prison system, which has been overcrowded for years and, absent significant action, will face even greater overcrowding in the years ahead.

The report notes that Washington’s push for austerity is aggravating the problem. The federal prison population has grown by almost 40 percent since 2001, but the budget for the Bureau of Prisons — after rising by about a third between 2001 and 2011 — has fallen by nearly 12 percent since then. And costs for services like pre-trial detentions have more than doubled over the past 12 years. According to the White House budget, the cost of incarcerating federal prisoners is expected to continue to grow, and the Inspector General notes that there’s “no evidence that the cost curve will be broken anytime soon.”

Some of that cost growth is the result of an aging prison population. According to the report, in just the past three years, the number of inmates over the age of 65 has grown by almost a third, while the population under 30 fell by 12 percent. “Elderly inmates are roughly two to three times more expensive to incarcerate than their younger counterparts,” according to the review.

Several factors have contributed to the growing numbers held in federal facilities. Primary among them is a longstanding trend of prosecuting more cases that had previously been handled by state and local courts in the federal system.

By one estimate, the number of federal criminal offenses grew by 30 percent between 1980 and 2004; indeed, there are now well over 4,000 offenses carrying criminal penalties in the United States Code. In addition, an estimated 10,000 to 100,000 federal regulations can be enforced criminally.

Previous Inspector General reviews had found that programs which might have eased the overcrowded system – like a compassionate release program for sick and infirm inmates, and another that allows foreign nationals to serve out their sentences in their home countries – have been underutilized and/or badly mismanaged.

A growing prison population and a shrinking budget for housing it is also creating serious security problems. The report notes that while the ratio of inmates to correctional officers in the five largest state correctional systems was 6-to-1 in 2005, the federal system has 10 inmates for every officer.

Earlier this year, Attorney General Eric Holder released the DOJ’s “Smart on Crime” initiative, which, among other reforms, directs prosecutors to avoid filing charges carrying long mandatory sentences against drug offenders unless they are violent, connected to cartels or gangs, or have significant criminal histories. But the IG’s report suggests that the impact of these changes may be limited because many of these offenders would have already qualified for a “safety valve” that Congress created in the 1990s which allows for their early release.

The problems detailed in the Inspector General’s report merely scratch the surface, as around nine out of 10 prisoners are held in state and local facilities. According to a 2012 report in The New York Times, state spending on prisons is now growing faster than any other budget item other than Medicaid. California now spends more on its prisons than its education system – a stark reversal from thirty years ago, when it spent three times as much educating its citizens than locking them up.

Further reading: Liliana Segura’s report on the growth of the private prison industry in The Nation,and the Center for Constitutional Rights’ fact sheet, “Torture: The Use of Solitary Confinement in US Prisons.”