"Two people have been successfully prosecuted for refusing to provide authorities with their encryption keys, resulting in landmark convictions that may have carried jail sentences of up to five years."
Forgetting your passwords is now officially illegal!
Encryption tools with built-in plausible deniability such as Truecrypt have been around for some time already, and "they" know about it.
However, the premise that made it attractive was the whole innocent-until-proven-guilty bit. Which doesn't seem to be of much concern to a populace scared of terrorists, child pornographers and its own shadow.
Also, Truecrypt can only beat a superficial scan. As soon as they get into patterns and headers, the nature of the encryption data should become apparent.