A PSN Tough Guy is someone who talks shit on Playstation network, When in reality he is just a big pussy trying to be a hardass. This is commonly seen on COD2 and oddly enough Little Big Planet. A PSN Tough Guy has two other cousins, The X-box live Tough Guy and the ever classic Telephone Tough Guy.
Monza900: Goddamit I got Shot in the face!Fag
PSNToughGuy: I shot your mom in the face las night!!#VAG
Monza900: Looks like we have a PSN Tough Guy