I have a colleague / acquaintance who worked laboriously to prevent photos of himself being put online. He avoided all social media, tried to duck out of group photos and used pseudodyms for fora. Searching for him only returned photos of other people sharing his name.

Then one day last year he attended an open-day about retraining IT professionals as teachers. He didn't read the small print closely enough and photos taken at the event were published and studiously tagged by the event organisers. There he was, bubbling up on Google Images.

Subsequently he contacted the organisers and they did remove the tagging, but it was purely by chance that he had discovered it.