I think we've decided mostly that this photo is obviously face-tinkered... but for the sake of the scrutiny, the graphic on the black T-shirt the one kid is wearing appears to be from the movie "Storm Trooper," which is from 1998. And then we remember the comment about the kids wearing "thrift store clothes," from which we would presume that the shirt could then be several years old.
I can't make out what the designs are on the hats. The one on "Nathan's" shirt looks like it says "Newport."