If they take pictures.....they have to haul some of that crap outta there....thats the deal...Would you find it strange if someone came to your garage sale and started takeing pictures in your garage?
I'm not saying OP was taking pics, but i would get suspicious real fast if it appeared that someone was casing the junk in the garage.
I have always asked if i could take a pic first, but maybe it's because I'm considerate.