I also got rid of the people I don't know.I did think while I was doing it, that everyone has photos of everyone else, so another family might be chucking out photos that had YOUR parents on, that you would have love to have seen, and we are doing the same to theirs. It's a shame but it has to be done, as previous posters have said, less for others to sort out after you've gone, or who's children also might keep a photo for sentimental reasons, not realising it was a next door neighbour of someone's Auntie and nothing to do with them or us AT ALL !!!!
I've got a huge box full of family photos , my husband can't see the point, he thinks we should just have them all on a memory stick as we have with the more modern photos. However, although I don't get the photos out often, they are a comfort and a joy when I do look at them.