DC Internet Safety Social Media

I checked into my privacy settings on Facebook.  I had done this a year or so ago and set everything to only friends could see things.  I had this set to friends of friends before that and started to get friend requests from so many people that I did not know, I changed the settings to friends.  I was surprised to see that a couple of the settings that I thought I had changed were not changed, so I did change them!  

I had the same problem. Friend requests from strangers. I delete anyone I don't know personally even if one of my friends is friends with them.