Little of what they examine has to do with civil liberties—cough, cough, ahem (this is a favorite critique of mine for my ACLU friends)—but the report does find that five out of six location-based providers are unclear about whether they require a warrant before handing information over to the government. Facebook is the winner here. Yelp, Foursquare, Gowalla, Loopt, and Twitter are unclear about whether they protect your location data from government prying.