With that book in hand (and I don't know how many copies were actually made) any resourceful bad guy could knock off about 60% of Brazil's phone and data network.
Reminds me of an instance in 2009. I was working in Santa Cruz, CA. I was configuring some of our servers remotely, when suddenly I lost internet connection. The whole office was out. VoIP was down - no signal on my cell phone as well. I went to the front desk and tried the land line. No dial tone.
This was weird.
I saw a few people from other offices milling about the courtyard. I went outside. They were all experiencing the same thing. A few of us went to Starbucks. Couldn’t buy coffee because their registers were down.
At this point, people were starting to leave their offices in droves. Santa Cruz PD actually began to have a few officers walk around the area, since no one could make phone calls.
The only thing that worked was Verizon cell phones. These were being passed around so people could make calls (data did not work however).
All in all, this lasted about 6 hours.
This was caused by a single frustrated former ATT employee. He just went in and clipped some fiber lines and left.
At least this is my experience with pharmacy billing. If we couldn't put claims through due to network problems, we'd just estimate based on your previous claims and keep things humming along.
The register - I speculate - is also tracking inventory. Ring up two cappuccinos and a pastry, corporate keeps track and knows what and when to re-order.
Getting the inventory out of whack might be worse than loosing trade during the outage.
I worked in places that made it difficult even for employees with a need to know to access network data and locations of wan fiber connections. Half the time, the cables are clearly marked on the street -- in New York, you call 611 and a team of people will draw on the street the locations of all telecom, electric, water, sewer and other infrastructure right on the street for you.