Spencer Hsu and Ann Scott Tyson of the Washington Post offers "Pentagon to Detail Troops to Bolster Domestic Security" (link), which is currently being linked by Drudge:

The U.S. military expects to have 20,000 uniformed troops inside the United States by 2011 trained to help state and local officials respond to a nuclear terrorist attack or other domestic catastrophe, according to Pentagon officials.

The long-planned shift in the Defense Department's role in homeland security was recently backed with funding and troop commitments after years of prodding by Congress and outside experts, defense analysts said.

There are critics of the change, in the military and among civil liberties groups and libertarians who express concern that the new homeland emphasis threatens to strain the military and possibly undermine the Posse Comitatus Act, a 130-year-old federal law restricting the military's role in domestic law enforcement.

Since few people like the ACLU (quoted in the article) and there are few libertarians, one might hope that the WaPo could have found others to oppose things like this. For instance, what's the incoming Barack Obama administration's take on this scheme? I'm sure I know the answer to that, and it's different from "change".

And, from this:

As Alex Jones exposed back in the late 1990’s, U.S. troops have been training for this eventuality for a considerable amount of time. During numerous urban warfare drills that Jones attended and reported on, troops were trained to raid, arrest and imprison U.S. citizens in detention camps as well as taking over public buildings and running checkpoints. During role playing exercises, actors playing prisoners would scream "I'm an American citizen, I have rights" as they were being dragged away by troops.

The contention that the troops will merely help "recovery efforts" after a major catastrophe is contradicted by the fact that Northcom itself, in a September 8 Army Times article, said the first wave of the deployment, which was put in place on October 1st at Fort Stewart and at Peterson Air Force Base in Colorado Springs, would be aimed at tackling "civil unrest and crowd control".

After a controversy arose surrounding the admissions made in the Army Times article, Northcom retracted the claim but conceded that both lethal and non-lethal weaponry traditionally used in crowd control and riot situations would still be used in the field.

There are videos of Marines conducting training exercises inside the U.S., in one case including in their training someone who identifies himself as being from a foreign force (the Dutch Marines). Some news articles about past training exercises are here, here, here, and here.

Also see September's Permanent U.S. Army brigade to help with "civil unrest and crowd control"... inside the U.S. (non-lethal weapons).