My hobby :

Showing people in the bay area this photograph and asking them if they've seen the new Apple HQ

https://en.wikipedia.org/wiki/Government_Communications_Head...

Ah sorry, I figured that after all the Snowden leaks the intelligence service acronyms were widely known on HN. GHCQ were particularly prominent in many of the leaks

a.k.a "The Doughnut" because of the shape of the building: [0]

// For non-Brits, 'doughnut' = 'donut'

[0] https://en.wikipedia.org/wiki/The_Doughnut