Remember back in 2005 or so when Immigration and Customs Enforcement (two "duties" the government would do better not to bother with) announced a targeted program to go after dangerous immigrant fugitives, potential terrorists and known criminals who had slipped through the faultless U.S. justice system? The ICE men knew they couldn't get all the illegal aliens, so they would focus on the truly dangerous ones.
Didn't last long, as newly available documents show. It turned out that going after criminals clever enough to have eluded the justice system by jumping bail or whatever, aren't that easy to catch, and sometimes they can be dangerous. So, as they have done with the misbegotten drug war (another foolish and in my view unconstitutional program), the enforcers started going after easier targets. In the drug war the tendency is to go after pot smokers, low-level "mules" and the occasional meth lab in a low-rent neighborhood -- or a cannabis dispensary in a state that has authorized medical marijuana. The big traffickers are sometimes too clever to be caught or better armed. In the immigrant war, by 2006 they simply started raiding homes where mostly peaceful but undocumented immigrants were believed to be. So they arrested mostly people with no criminal records or even deportation orders against them. By 2007 only 9 percent of those picked up had a criminal record.
When government bans something it has no business banning, it not only creates a new and usually violence-prone criminal underground, it creates a situation where the authorities increasingly go after generally peaceful people whose non-harmful activities or pursuits the government has arbitrarily outlawed. They always say it's to protect us from dangerous people, but it turns out the authorities have little taste for confronting the dangerous ones. So we get less safe as well as less free.