Snowdens document leaks happened in 2013 (implying the surveillance state was set up well before then). So this is more a leisurely stroll than a sprint.
Room 641A was leaked in 2006. To some extent, this all started in the 1940s with the Enigma and JN-25 code breaks. After that, everyone knew that intelligence was the future of power.
Unfortunately while evocative, it doesn't really make sense.
A Zamboni has a "conditioner" at the rear that contains a sharp horizontal blade that shaves the ice as the machine runs across the ice. The blade is a bit like a very wide wood-plane. It is sharp and controlled to be a little below the current surface of ice. The shavings are moved to a waste tank using an internal horizontal auger and vertical auger.
You usually couldn't get near enough to the blade to have a close enough shave for it to harm you. However I'm guessing a Zamboni could hurt you in other ways.
Disclaimer: I only skimmed the details . . . I'm sure applying the right amount of intelligence could discover harmful means.
Anyone who had read Bamford's books on the NSA many years prior to 2013 took a look at what info came out and had an internal thought process like "this is nothing new at all".