Resolving privacy/security issues: geolocation based services

When you leave your house, do you leave the windows open and doors unlocked? Why not? No one would know unless they tried to get in if they were truly open, right? When you park your car, do you leave it unlocked? Why not? No one would know unless they tried to break in, and what are the odds of that? When you leave the house, do you check into a geolocation based service to announce where you are? Why not? What are the odds of something bad happening, right? See the twisted logic? Let’s talk about some solutions to the security and privacy issues surrounding these services so everyone can have fun.