There is general recognition that the security situation in Baghdad and some other parts of Iraq has got significantly better in the past three months or so.
There are thought to be nearly 80,000 of them nationwide.
Many of them used to fight alongside the insurgents, but now, encouraged by their tribal leaders, they have turned against al-Qaeda and are helping keep it out of their areas.
We went to al-Ameriya, a journey we would not have dreamt of attempting just a few months ago, to see some of the local fighters in action.
This part of Baghdad used to be a stronghold of al-Qaeda or groups linked to it.
Knights of Mesopotamia
Now we are travelling, not with the American army as we might once have done, but with a tribal Sunni sheikh whose followers are now controlling the area along with the Americans, helping to drive al-Qaeda out and to keep it out.
We are under the protection of the Fursan al-Rafidain, the Knights of Mesopotamia, a force of about 600, and they clearly rule the roost in al-Ameriya.
They are paid and supplied with uniforms by the Americans, and work closely with them. Our first stop was at their headquarters.
Their leader, Abul Abed, meets the Americans every day.
On the wall is a picture of him with General David Petraeus, the top US commander in Iraq.
But it was not always that way. Before turning against al-Qaeda, he used to be in an insurgent group which fought the Americans.
"At the beginning, people saw it as an occupation which had to be resisted. But then they saw that the Americans were working in the interests of the people.
"They saw al-Qaeda doing terrible things. They were killing Sunnis, Shias, and Christians. There were bodies everywhere, being eaten by dogs. So we had to fight them," Abul Abed said. continued
[I have to say this: why didn't they fight Al Qaeda until recently? Is it because they weren't getting paid?]