Privacy through fake data?
This was the idea behind paranoid linux which began as fiction and became a real project that did not reach fruition:

"Paranoid Linux is an operating system that assumes that its operator is under assault from the government (it was intended for use by Chinese and Syrian dissidents), and it does everything it can to keep your communications and documents a secret. It even throws up a bunch of "chaff" communications that are supposed to disguise the fact that you're doing anything covert. So while you're receiving a political message one character at a time, ParanoidLinux is pretending to surf the Web and fill in questionnaires and flirt in chat-rooms. Meanwhile, one in every five hundred characters you receive is your real message, a needle buried in a huge haystack.
~Cory Doctorow (Little Brother, 2008)

When those words were written, ParanoidLinux was just a fiction. It is our goal to make this a reality. The project officially started on May 14th, and has been growing ever since. We welcome your ideas, contributions, designs, or code. You can find us on freenode's irc server in the #paranoidlinux channel. Hope to see you there!"

I think the most modern equivalent is Pirate Linux along with the TOR Project.

BTW, Cory Doctorow's book "Little Brother" is kind of a fun read if you are a geek.  If you are reading this then you probably ARE a geek :-)

The reality is that it is very difficult to hide one's true intent when high quality clustering, classification and anomaly/novelty detection is used.  I work with guys who have done this type of behavior detection for some very high profile three letter agencies and it is very very easy to detect nefarious behavior if you have enough data.  So much so that undercover good guys sometimes clearly show up in the data sets.