Ha! I assumed the Cargo Socks were real. They would have been a hit in my day.
I honestly don't know if this was a "Marine" thing, or all services, but we were not supposed to carry anything in our dress uniform pockets. So the go to place for your ID, wallet, smokes, and just about everything else was your socks. To be honest, I still do this on occasion today depending on the fit of the trousers or suit I am wearing.
Now however, it seems totally acceptable (at least for MIDNs) to walk around in uniform with a smart phone in their front trouser pocket. It is especially noticeable in Summer whites. I think it looks awful.