I like the idea of a stranger being able to access my contacts
You have a refreshing view of humanity that you think there are so many more trustworthy people than dishonest. I'm a grump and figure it's far more likely anyone finding an unlocked phone will wipe it and sell it on craigslist since there's no activation lock in place. The crook will have it powered off or SIM removed long before you can get to where you can do a remote wipe.
If you lose the phone and it's locked, an honest person seeking to return the phone will have it powered up and likely where it gets cell signal. The message you send via FindMyiPhone will pop up on the screen telling them how to contact you.
Alternately if you're concerned with the phone not getting signal for some reason and FMiP not working, there's the low-tech option of a slip of paper with an alternate phone number between the case and the back of the phone. Or use the high tech option of adding the alternate phone# to your lock screen background image.
Or even better yet -- with iOS8 you can set up whatever info you want under Medical ID in the Health app and set it to be displayable on the lock screen under "Emergency".
So that's at least three solutions to allow a lost locked phone to find its way home...
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thought it's one of those posts being afraid of conspiracy theories around them.
Just because I'm paranoid doesn't mean they're NOT out to get me!