(CBS News) NEW YORK CITY - One of the biggest parties in the world requires a massive counterterrorism operation. On New Year's Eve, CBS News got a rare inside look at how the FBI keeps Times Square safe.
It's a celebration seen by a billion people on TV and a million people at the crossroads of the world.
Those huge numbers make the law enforcement math simple.
"It's a nice target -- a lot of media, a lot of cameras -- to expose the world to whatever some insane person has got planned. It's a target," said Randall Derouin of the FBI.
That's why Derouin and his FBI "SWAT" team were positioned nearby in an underground garage - cars loaded.
"We have specialized optics -- night-vision optics -- in here for our rifles," Derouin said.
In the front seat: Body armor and an M4 assault rifle.
"If we're called somewhere it's because something really bad has happened - and it requires us to have a good show of force," Derouin said.
The New Year's Eve operation took months of planning. They were prepared for anything from a terrorist attack to a lone gunman.
Assistant Director in Charge George Venizelos called New Year's Eve the FBI's "Super Bowl".
"If anything happened or anything of a terrorist nature it would cause mass chaos," Venizelos said.
CBS News rode along with some of the FBI agents. There were more than 100 of them, who joined thousands of New York City police officers.
Kris Kottis, a 23-year FBI veteran, is a long-time New Yorker who says she looks for anything unusual.
"It's what's happening where everyone doesn't see where a lot of things are going on," Kottis said. "There's a lot of different components the FBI has. The NYPD has components -- hazmat, radiologocical teams. There are sharp-shooters. There are surveillance teams. There are under-cover officers in the crowd."
The partygoers are monitored on cameras, and radiation detectors check for threats the revelers cannot see.
A block away, an FBI bomb squad showed CBS News the special suits used to diffuse bombs.
Luckily, there were no major incidents on New Year's Eve, so most of the equipment stayed packed away in unassuming SUVs.
Of the spectacle that is Times Square, what may be most remarkable is what you never see.