The death of Syme, which appears to have gone offline some time in the past few months, is testimony that even in a booming market like social networking, there will be winners and losers.
Syme allowed its users to chat and share content over a fully encrypted network. The site launched not long after Edward Snowden blew the lid off the U.S. government's aggressive surveillance tactics, which created an appetite for greater security and privacy on the Web.
"The website is no longer running," Syme co-founder Louis Mullie said Friday in an email. He and his fellow co-founders didn't respond to messages seeking further details.
The site appears to have been operating on Aug. 29, judging by a snapshot taken by the Internet Archive's Wayback Machine.
Syme's most recent tweet was in April, when it said it had addressed the Internet's Heartbleed security bug.