David Cameron, the British Prime minister, is one-upping his Western allies when it comes to anti-encryption propaganda. Ahead of national elections in May, Cameron said that if re-elected, he would seek to ban encrypted online messaging apps unless the UK government is given backdoors.

"Are we going to allow a means of communications which it simply isn't possible to read?" Cameron said Monday while campaigning, in reference to apps such as WhatsApp, Snapchat, and other encrypted services. "My answer to that question is: 'No, we must not.'"

He said the Paris attacks, including the one last week on satirical newspaper Charlie Hebdo, underscored the need for greater access.

"The attacks in Paris demonstrated the scale of the threat that we face and the need to have robust powers through our intelligence and security agencies in order to keep our people safe," Cameron said.

To be sure, it's not known if Cameron could carry out his threats, but they are part of a global government anti-encryption theme. Last week, a Spanish judge reportedly ordered the detention of several suspected terrorists because, in part, they "used e-mails with extreme security measures, such as the RISE UP server." Rise Up, the Seattle company that offers encrypted e-mail services, responded in a blog post titled "Security is not a crime."

Encryption became a hot-button topic in the wake of the summer 2013 leaks by National Security Agency whistleblower Edward Snowden. His documents, including some last week seemingly showing that Skype has a backdoor, highlighted a broad online global surveillance society and set off a cottage industry of encryption companies.

What's more, Apple began making its latest mobile phones encrypted by default, and Google did the same with the Nexus 6, a move that likely prevents authorities from physically accessing contents directly from these phones' hardware, even with a warrant.

Attorney General Eric Holder and FBI Director James Comey are urging industry to give the US government backdoor access to their encrypted wares. The response, at least publicly, was an overwhelming no.

"People have a right to privacy," Apple Chief Tim Cook told PBS News in September.

Holder said encryption "emboldens" criminals.

"Recent technological advances have the potential to greatly embolden online criminals, providing new methods for abusers to avoid detection," Holder said in an October speech. "In some cases, perpetrators are using cloud storage to cheaply and easily store tens of thousands of images and videos outside of any home or business—and to access those files from anywhere in the world. Many take advantage of encryption and anonymizing technology to conceal contraband materials and disguise their locations."

Comey said he was concerned about "companies marketing something expressly to allow people to place themselves beyond the law."

Unlike Cameron, Comey and Holder never threatened to ban encrypted services.

In the United States, the law surrounding this issue is the Communications Assistance for Law Enforcement Act of 1994, commonly referred to as CALEA. It requires that telcos make their phone networks amenable to wiretaps, but it doesn’t apply to phone hardware or most other communication services—at least not yet. Congress hasn't backed Comey or Holder's words with legislation.