Not everyone is comfortable with carrying a weapon, and that's fine. A reverse image search can determine if a profile picture is being used elsewhere on the internet, and on which websites it was used. Few normal people would make this much effort—but for a cybercriminal, the easiest way to create a fake profile is to use glamorous pictures from the web, shot by professional photographers.
So you would be OK if a stranger you're about to go on a date with asks you for your cell phone and then starts calling people in your address book? Listen, and respect what they say. Type keyword s to search.