30 people who really should have checked the background of their photos before posting them online

Addresses. Keep your postal address and your main email address private. That doesn’t guarantee it won’t fall into the wrong hands — postal addresses, for instance, are a matter of public record. Set up and use a “disposable” email address for posting — either one you can delete if it gets into the hands of spammers or a different one for each time you have to give it.