Those arent the Marines, this photo is from Operation Overlord the amphibious invasion of Normandy in June 1944 to my knowledge the USMC didnt use helmets with that netting just plain or with the camo cloth but I could be wrong Im not American
As I posted on io9.com when this poster was featured in a gallery:
This one is undoubtedly my favourite in the bunch. Understated but eye catching, with a single element that makes it immediately clear what the movie is about. It makes you give a double-take as you almost skip over it, then stop to analyze it. The perfect teaser poster.