A great example of just how much knowledge and expertise is available via the internet occurred recently on a local discussion forum, StroudGreen.org.
I posted up a very brief comment with a link to some news footage from the 1940s of the area, showing bomb damage caused by the Second World War.
Over the next couple of days people filled in huge amounts of information, including someone who matched up the 1940s footage with Google Streetview to identify the building, bomb damage maps, links through to specialist information available elsewhere and even a first hand account of growing in the area in the 1940s, complete with memories of the bomb damage.
Very impressive.
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