Someone showed that to me a few weeks back.
I post very little on Facebook and have deleted anything I've ever posted that may have possibly been of interest to anyone, but there were 6 or 7 people, all of whom appeared to be from outside the U.S. following me. Kinda weird.
I don't know that the reasons for strangers following you on Facebook are necessarily nefarious though. For example, my youngest showed me how to set up my Twitter account. I posted one tweet, an experiment just to see it work, and by the next day, 11 people were following me. My daughter said that people will follow you "just because." And in the social media-verse, that makes as much sense as anything else.