Apple has taken down an app that uses crowdsourcing to flag sightings of U.S. immigration agents, apparently after being pressured by U.S. authorities. ICEBlock, a free iPhone-only app lets users anonymously report and monitor activity by Immigration and Customs Enforcement (ICE) officers, was no longer available on Apple's App Store as of Friday. "We just received a message from Apple's App Review that #ICEBlock has been removed from the App Store due to "objectionable content',", the developer said in a social media post.