iPhone expert Jonathan Zdziarski recently discovered what he thought was a remote killswitch for iPhone apps: a blacklist located at https://iphone-services.apple.com/clbl/unauthorizedApps. He thought it could be used "to disable applications that the user has already downloaded and paid for." However, Daring Fireball's John Gruber found out from a source that the list only serves to prevent malicious apps from accessing location information.
In order to test the blacklist out, I set up a DNS server on my Mac that pointed
iphone-services.apple.com to my own web server. I then added the
unauthorizedApps file in the
clbl directory of my server. I switched the iPhone to use the DNS server on my Mac when on my WiFi network, and then tested the blacklist URL in Safari. It worked, so I tried modifying the file to block the Maps app from getting location info:
When I opened the Maps app and told it to find my location, it gave me the following error message:
Otherwise, it worked normally. Once I removed the Maps app from the blacklist, it could find my location once again.