sounds like a great tool for stalkers...seems like a rather bad idea.
Hope it doesn't work out that way though.
EDIT:
Pretty cool app for parents keeping track of their kids though.
There has been a lot of misconception about these location based social network apps. With the iPhone version of both, you have to confirm someone as your friend so they can see your current location (and current locations are only taken when the app is opened, so it's only when given it permission to do so). Unless the stalker is your best friend (or you're a complete idiot), there is little danger in these sorts of applications. Try out an application first before you start getting paranoid about it.