More than a billion people on the planet use online messaging service WhatsApp to send and receive messages, photo and videos and to make phone calls over the Internet. Most of WhatsApp’s users are outside the United States.

A subsidiary of Facebook since 2014, WhatsApp just announced the addition of end-to-end encryption to every form of communication on its service. This means all of your messages, phone calls, photos, and videos sent or received over WhatsApp are encrypted. It also means that if the WhatsApp service is running on your phone, your phone is also encrypted.

End-to-end encryption makes the service secure from hackers and other third parties. In addition, the encryption prevents even WhatsApp employees from accessing your data sent over the service.

Law enforcement has stated that the encryption security makes the service popular with criminals and terrorists. The end-to-end encryption means WhatsApp cannot comply with a court order to provide law enforcement access to your messages, phone calls, photos, or video content. In at least one current case, which remains under seal, WhatsApp maintains it is unable to comply with a federal judge’s order to wiretap for a WhatsApp user.

Many lawmakers have called for companies like WhatsApp to equip their encryption schemes with a backdoor available only to law enforcement. Some lawmakers seek legislation requiring back doors. The FBI and the Justice Department maintain they are only trying to keep the status quo – to be able to wiretap a phone call or email with a warrant in hand.