The PirateBrowser behaves a bit differently, however. From its website:
No, it's not intended to be a TOR Browser, while it uses the Tor network, which is designed for anonymous surfing, this browser is ONLY intended to circumvent censorship. The Tor network is used [in the PirateBrowser] to help route around the censoring/blocking of websites your government doesn't want you to know about.
To drive home the point that the PirateBrowser isn't designed for anonymity, it doesn't include the encryption-providing "HTTPS Everywhere" plugin found in the Tor Bundle.
Additionally, the PirateBrowser only accesses Tor when you're using the browser to try to access a blocked website. Non-blocked websites are delivered to your browser normally, rather than hopping all around.
Anonymous messaging with Tor
While the drastic uptick in usage is probably mostly attributable to the PirateBrowser--the Pirate Bay's custom browser was downloaded more than 100,000 times in a matter of days--the Lavabit and Silent Circle shutdowns likely also drove privacy-minded people further underground.
Tor itself isn't an email provider, though--it's just anonymizing routing technology, pure and simple. What's more, the most popular Hidden Service email provider in Onionland, Tormail, was recently killed by the U.S. government. It was collateral damage in the takedown of a service provider hosting many of the Web's child pornography sites.
That's not to say Tor can't be used to send secure messages online, however.
Signing in to a webmail account while using Tor will obviously give your identity away, but using Tor in conjunction with dummy email accounts and PGP encryption would deliver a relatively strong level of privacy. Privacy buffs can also take advantage of Onionland's messaging services, which deliver a very high level of anonymity.
No matter what accounts for Tor's dramatic spike in popularity, one thing's for certain: More people than ever are turning to technology to spite Big Brother.
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