The ICEBlock application contains flaws:

The creator of ICEBlock, an iOS application for discreetly reporting encounters with US Immigration and Customs Enforcement (ICE) officials, asserts that it “guarantees user confidentiality by retaining no personal information.” However, this assertion has faced criticism. ICEBlock developer Joshua Aaron has been alleged to have made misleading claims about user anonymity and confidentiality, being “misguided” concerning the privacy features provided by iOS, and of being an Apple enthusiast. The concern isn’t what ICEBlock retains. It’s about what it might inadvertently expose through its close integration with iOS.