The Intercept claims to have identified 8 major U.S. cities that have a building where the NSA spies on telecommunications through AT&T facilities. Here is the photo from the story of 10 South Canal Street in Chicago as well some of the background of the building:

10 South Canal Street, Chicago, IL

Like many other major telecommunications hubs built during the late 1960s and early 1970s, the Chicago AT&T building was designed amid the Cold War to withstand a nuclear attack. The 538-foot skyscraper, located in the West Loop Gate area of the city, was completed in 1971. There are windows at both the top and bottom of the vast concrete structure, but 18 of its 28 floors are windowless…

 

10 South Canal Street originally contained a million-gallon oil tank, turbine generators, and a water well, so that it could continue to function for more than two weeks without electricity or water from the city, according to Illinois broadcaster WBEZ. The building is “anchored in bedrock, which helps support the weight of the equipment inside, and gives it extra resistance to bomb blasts or earthquakes,” WBEZ reported.

Today, the facility contains six large V-16 yellow Caterpillar generators that can provide backup electricity in the event of a power failure, according to the Chicago Sun Times. Inside the skyscraper, AT&T stores some 200,000 gallons of diesel fuel, enough to run the generators for 40 days.

NSA and AT&T maps point to the Chicago facility as being one of the “peering” hubs, which process internet traffic as part of the NSA surveillance program code-named FAIRVIEW. Philip Long, who was employed by AT&T for more than two decades as a technician servicing its networks, confirmed that the Chicago site was one of eight primary AT&T “Service Node Routing Complexes,” or SNRCs, in the U.S. NSA documents explicitly describe tapping into flows of data at all eight of these sites.

It is common that cities have buildings that may be hiding something, ranging from telecommunication structures to power substations to fake facades to hide subways or rail lines. But, I assume very few people would guess that a rather normal looking city structure could be part of an Internet surveillance program. I’m not sure what people would do with this knowledge. Protest outside? Give it a wide berth by not traveling near it? Chalk it up as a local oddity and then move on with normal life?