American Military Police in Iraq are rediscovering the same problems that were encountered running wartime prisons for enemy captives since as far back World War II. While the 9,000 captive Iraqis being held in prisons are not prisoners-of-war (POWs), and most are released after brief questioning, many are hard core terrorist types. These thugs tend to get organized, and nasty, even while locked up.
In Iraq, its a replay of World War II, where hard core Nazis among prisoners, would get organized, terrorize the anti-Nazi, or indifferent Germans, and carry out attacks on the guards. Same thing with hard core communists during the Korean and Vietnam war. Now, in Iraq, you have the Baath Party and Islamic radicals organizing trouble. These fellows have lots of experience in terrorizing Iraqis, and would use less radical prisoners as cannon fodder. For example, at prisons like Abu Ghraib, the guards would have to fire rubber bullets several times a day, just to deal with groups of aggressive prisoners. Usually a couple of Baath or Islamic toughs using less militant, and cowed, prisoners, as shields. Guards would regularly sweep prisons for weapons, and find dozens of homemade nasties. Even with informers among the prison population, the hard core guys were able to organize large scale violence, and nearly get riots going once or twice a month. MPs have found that their guard dogs work very will with prisoners, partly because Arabs, for cultural reasons, dont like dogs (which are considered dirty.) So the guard dogs are very good at controlling small groups, but risk getting ripped apart if theres a large fracas.
All this is old news to anyone who knows about the very similar situations dating back to the 1940s. Even though todays prison guards have closed circuit TV, rubber bullets (and other non-lethal weapons), its still a nasty business.