Long long ago when I had my first gf I did some research on her to know if talking to her was really worth it. You know, small things like digging her and her family's social media. When I talked her irl for the first time I already knew her full name and some of her interests. When I showed her a social graph I collected pointing at a red circle in the middle saying 'look, this one's you' all she said was 'oh, ok, cool'. But maybe I was actually extremely lucky and most people would actually freak out?
Pro tip: if you are trying to collect info on someone, check their parents. Some people (me) are extremely paranoid and have near zero public social media presence, but older people are usually not that tech- and privacy-savvy and can for example post pics you would not find on person's profile directly.