Why are my facebook friends so mean?

[Samantha]

I am only friends with people I know so I don't have any more than 200 friends on facebook, and they are all high school classmates and teachers mostly. I used to use it frequently and the last time I did that I ended up getting deleted by 5 different people in a one week period (I don't go on emotional rants or treat it like my diary, I just post pictures and talk about life sometimes when I have no one to turn to). I went internet free for a few months and then I used facebook again just barely now I get on a couple times a day to check notifications. The past two days I have posted around ten pictures of scenery that I took with my iPhone but I don't post anything annoying and I got on today only to discover I was deleted again by someone else. What am I doing wrong here? Are people that I'm friends with just mean? I hate clicking on my name and getting on my profile because I hate to see people deleting me all the time.