This is the link (I get a “do not have permission to access” message). It shows up in google searches (I searched “sdmb snowden privacy”), and the thread is called “Does the general public really care about NSA/Snowden datamining”.
What happened to this thread?
Generally speaking when you get that message that means the user that made that post has been banned. Contact a moderator off the board for more information.
The NSA got to them! 
That’s what they want us to think! 
Nitpick, since this is the 'Dope…I believe this means the message/thread was either deleted, or moved to a location that we don’t have access to. The user being banned doesn’t cause this behavior.
It was moved to a location that you have no access to. Correct.
The user is almost always banned, which causes the thread to be moved from sight.