I wanted to expand the case described in this question.
Probably the topic is more related to security, but I feel like I don't know enough about this, and probably someone might explain better and in simpler terms what's exactly going on.
As mentioned in the cited question, I also did some test in Google Drive. Create a new file, select the option of sharing a file with
Anyone with the link ("Anyone who has the link can access. No sign-in required."). Still no visitors. I didn't share the link, not open the link in new tabs, nor the file itself in another browsers. Didn't do anything at all.
At this point I started coping and pasting the link here and there: search bar on Google, random text file, random search bars. No sign of new visitors. But then I copied, just copied, the link in a text box of a Facebook chat I initiated with myself, and boom, got two new anonymous visitors on the file. Sent the message with the link, two more.
Who can explain me what's going on here? Do I have some security issues, or is some Facebook bot?
EDIT 1: Other relevant link that doesn't answer my question though.