Seen here eyeballing two hunks, Galdalf the Grey demonstrates his 'You Shall Not Pass' spell on the Bow Bridge in Central Park. SPOILER: Everybody passes. One dude even casts a Harry Potter spell on him as he goes by. If there had been an actual Balrog on one end of that bridge it would definitely be picking Hobbits out of its teeth right now.
Keep going for the video.
Thanks to lilco, who agrees Gandalf may need to lay off the magic tobacco for awhile and hit the spell books harder.