If you're into games, there's a good chance you've heard of Dark Souls, an infamously super-hard game surrounded by a community that's almost as impenetrable as some of the game's own systems. (t3.com)
I'll never forget seeing the armed police guards constantly posted at my Metro stop, getting swabbed for Anthrax (Bacillus anthracis bacteria) after setting foot in my local post office, enduring countless Code Red (i.e., severe) Homeland Security Advisor System warnings to tape my windows shut, and witnessing the massive hole bored deep into the seemingly impenetrable walls of the Pentagon during my drive to work. (patrickmahaney.com)
Jedinak and McCarthy would be a nigh on impenetrable barrier in front of the back four and this option could lead to Bruce deploying a highly effective 4 -2-3-1 — a formation that would give Grealish the perfect opportunity to wreak havoc in a free role. (caughtoffside.com)