Comment by JoeSmithson

> "GCHQ has a program called ROYALCONCIERGE, where they hack the reservation systems of hotels to watch for targets renting rooms"

Your own source makes it clear that this system works/worked by intercepting emails.

> "then GCHQ sends teams ahead of time to [...] assassinate them"

Unless Snowden buried the lede quite spectacularly, I think this is not true.