A very detailed report on the app highlighted its stalkerish-ness, and that was enough for Foursquare. They told the New York Times:
“This is a violation of our API policy, so we’ve reached out to the developer and shut off their API access."
Maybe it's a violation of their API policy, but we'd ask the question: when are people going to learn to lock down their privacy settings on these services?
Let's be honest; why does anyone really want to share their location?