Looking up strangers on Facebook
When I receive calls from suspicious phone numbers, I tend to search for the phone number on Facebook. If I’m lucky, I can find out who the person is if they have attached the suspicious phone number to their account. Other times I come up empty handed.
From a privacy standpoint, this is extremely creepy. Imagine you are a real estate agent who is trying to find new tenants to move in. One of the biggest mistakes that real estate agents make is to provide their phone number for contact which could also be linked to their personal Facebook account. If the relationship you build with a complete stranger goes sour, they could find you by looking up your phone number on Facebook Search.
Currently, there is a setting in Facebook to circumvent this privacy issue. You can limit the scope in which people can find you by your phone number.
This setting is set to Everyone by default. Facebook should look into changing this so that it is set to Friends by default.