the FBI is urging Americans to stop sending regular text messages between Android phones and iPhones the agency says the exchanges are vulnerable to hackers because they are not encrypted encryption is a technology that scrambles a message and requires a key to be able to see it so if you have an iPhone and you need to send a message to an Android User you're advised to use secure apps like signal or Whatsapp the warning comes amid high-profile recent hacking incidents that have been linked to to China