Someone who worked for the British Military told me back in the early 00's the US military (but could be any part of the US govt) had the ability to bowl up outside a building and "tune" into any of the pc they could detect. It didnt matter what floor of an office block they were on, how far away from a window they were, they had a special suitcase for remote accessing any and all pc's they wanted.

Dont know how true it was or is, but I've seen some of these devices now advertised online. I'd provide a link if only Google & Bing would deliver the results, and were also psychologically engaged in warfare on the population.