Barring law enforcement authorities’ access to encrypted communications would make it easier for Islamic State sympathizers to attack the United States, FBI Chief James Comey told Senate lawmakers on Wednesday. The Federal Bureau of Investigation is pushing technology companies to let law enforcement authorities have access to encrypted communications to investigate illegal activities. Those companies have resisted, arguing that such access would weaken systems against criminals and computer hackers. Comey has previously criticized Apple Inc and Google Inc for ramping up encryption. Comey told a US Senate Judiciary Committee hearing that Islamic State, also known by the acronym ISIL, is imploring supporters through Twitter to carry out attacks. Related conversations often take place via end-to-end encryption mobile communications that are unreadable to anyone other than those sending or receiving the messages.