I think that's why I'd never want to attend any sort of meet-up gathering... and that's why I'm vague about my exact location, my exact previous jobs, my husband's job, etc. I won't even share photos of my family because they can be "reverse searched" or people can use facial recognition on Facebook to zero-in on someone's identity.
You just never know if someone is who they say they are. Why take chances? I like most of the folks I interact with on DU... but I'm sure I've made some people angry at me... and I wouldn't be surprised to learn that I had "enemies" or "rivals" who would enjoy getting some sort of personal revenge on me (or just being able to harass me).
But I'm very happy to learn that DU has resulted in long-time friendships and romance for quite a few of you! That's great! 
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