I had a real clear out like you, a few years ago. I found quite a few photos were doubles, especially the school ones. I offered some to my children, and then binned any left over. I thought I’d made sure they were all shredded, but one small piece got away. I know this, because when the bin men left, and I went outside to fetch the bin, there was the face of my daughter, aged about 5, on a piece of school photo, lying in the road.
It made me feel really sad, even though I had a much larger copy, and a few small ones. I went for the landfill bin, then I knew they would burn.