Looks like an in-car GPS sent a group of tourists into a dangerous slum -- and a drug gang firefight -- in Rio de Janeiro.

http://www.canada.com/edmontonjournal/news/story.html?id=5530c87a-8740-404a-a81b-fa15050e64d2

No doubt GPS is highly useful, but it sure doesn't replace research, research, research into local conditions.