Silent Circle, an encrypted communications company co-founded by PGP creator Phil Zimmermann, has also seen an increase in interest since the NSA leaks, but the company didn't immediately have hard numbers.
In fact, Silent Circle decided to close down its secure email service shortly after learning that Lavabit, a secure email service used by Snowden, suspended operations instead of complying with U.S. government demands to turn over its Secure Sockets Layer private key.
Silent Circle, which continues to offer other encrypted communication services, shut down its email service without warning customers out of concerns that it would face similar government demands, said Jim Burrows, the company's vice president of engineering.
"We knew that there would be a fight eventually, that someone would want us to put a backdoor, a Trojan horse in, for law enforcement," Burrows said Wednesday at a Cato Institute event on NSA surveillance. "To suddenly see Lavabit go ... 'I'm going to close a company that's been open for 10 years because I've been put in an untenable position,' that's been really the hard thing."
The NSA or other government agencies that demand secure communications companies install backdoors are putting them in impossible positions, said Chris Soghoian, principal technologist and a senior policy analyst at the American Civil Liberties Union's Speech, Privacy and Technology Project.
"When the U.S. comes to a company like Lavabit and compels them to hand over their encryption keys, that is a death sentence to that company," he said at the Cato event. "If they comply, their reputation would be destroyed. Or, they could refuse to comply and shut down the service, and then they are dead, too."
Using an anonymizing service may not ultimately prevent the U.S. government from seeing your data, although it should make it more difficult, said Disconnect's Oppenheim, who has a former NSA engineer as the company's CTO.
Disconnect Search's FAQ includes information about possible government searches.
"The reality is the U.S. government may force us to begin logging the search queries of a particular user or group of users," the FAQ said. "If served with a court order that includes a non-disclosure provision, we may not be able to tell our users about this change for some period of time, possibly forever. And the U.S. government may also have other methods of monitoring user searches which Disconnect Search cannot prevent. "