You don't have to give any personal information. You don't even have to give your name. You can use a fake name, fake location, fake email account, etc. You can just sign up for the emergency notification services, leaving very little "signature."

The problem is that many people don't have the discipline. They find their friends online, or they like some celebrity's profile. They want to share the cat pictures. They want to yell at the news. At some point they start giving out personal information voluntarily, etc. People forget themselves and post their phone number and address in public places, thinking they're giving that information just to friends.