its VERY safe especially if you put your profile on PRIVATE by going to SETTINGS > PRIVACY SETTINGS > PROFILE and choose the ONLY FRIENDS option for everything
so when someone searchs you IF you come up it will say:
__________ (your name) only shares certain info with everyone to learn more about _________ add them as a friend
when someone adds you you can choose to CONFIRM that you know them and become friends OR IGNORE so you won't be friends
you can even block people by going to SETTINGS > PRIVACY SETTINGS > then go to the bottom and type the person's name in the box that yo wish to block
Source(s):
Hope I Helped