Two encrypted email services have shut down due to fears their customer data could fall into the hands of authorities.
The popular Lavabit mail service -- used by NSA diocument leaker Edward Snowden -- announced its closure last week. Silent Circle followed shortly after with a statement its encrypted email service Silent Mail would also be shut down.
The reasons for the closure remained unclear due to an apparent legal gag order imposed on Lavabit owner and operator Ladar Levison.
"I have been forced to make a difficult decision: to become complicit in crimes against the American people or walk away from nearly 10 years of hard work by shutting down Lavabit," Levision said in a statement.
"I wish that I could legally share with you the events that led to my decision ... As things currently stand, I cannot share my experiences over the last six weeks, even though I have twice made the appropriate requests."
His statement hinted that the email service may have been forced to hand over user data to the US Government, but it was unclear who the data related to.
The decision was seen as "the writing on the wall" for Silent Circle, which announced the closure of its email service hours later.
Co-founder Phil Callas said the decision to erase mail and wipe disks was pre-emptive of government requests for user data.
"We see the writing the wall, and we have decided that it is best for us to shut down Silent Mail now. We have not received subpoenas, warrants, security letters, or anything else by any government, and this is why we are acting now," Callas said in a statement.
"Email that uses standard internet protocols cannot have the same security guarantees that real-time communications has. There are far too many leaks of information and metadata intrinsically in the email protocols themselves. Email as we know it with SMTP, POP3, and IMAP cannot be secure."
Silent Circle had mulled phasing the service out and shutting it off to new sign ups but decided it was "better to be safe than sorry" with user safety in mind.
"... the worst decision is always no decision," Callas said.