The insurgents obviously allow journalists to follow them around, or at least give them access to their “side”, since essentially every day I saw similar footages of the insurgents on TV, taken during the fights (insurgent firing, using mortars, etc…). So, they let in not only photographers, but whole TV teams. Actually, I’m surprised that this picture puzzles you, because it appears quite ordinary to me.
Now, I wouldn’t know how it works in practice for these journalists have presumably to get the agreement of both sides to enter the combat zone in Basra, not even mentionning that standing besides people firing a mortar probably isn’t the safest place to be.
I’m not sure how they would have to protect their source, since they’re showing their face, anyway. The only thing I can think of is that they could report to the american troops “you know there’s a group of insurgent/ a mortar at such or such place”. My assumption would be that they won’t give this kind of information, in order to stay neutral and not endanger themselves or their colleagues in the future.
As for the last question, I would not be surprised if intelligence services pulled this trick on occasion. And some insurgents probably feel the same. A couple months ago, two french journalists were accused of being spies, detained for a couple days and threatened to be executed, until they managed to sufficiently convince some leader they were genuine journalists.
And by the way, refering to your title, all journalists aren’t “ennemies”. They’re supposed to always be neutral, and in any war, there will be journalists from actually neutral, or even sympathetic countries.
Personnally, if I were an insurgent in Basra, I would get paranoid and wouldn’t let a journalist taking my picture, but I suppose that if they think they’re heroes, and that they will ultimately win (rather than being eventually chased down and arrested after suffering a defeat), they would be, at the contrary, rather proud to be shown on TV, in the same way an american soldier could.