I'm not doing anything nefarious, but these days law enforcement seems ever more determined to gin up evidence and argument to suit their purpose. Also, if they can use the back door, how long until a malicious third party can?
Enclosed but not encrypted: http://www.h-online.com/security/features/Enclosed-but-not-e...
There would always be doubt, and some kind of parallel construction would surely be used to protect the secret technique.
I could see it being used in hundreds of cases per year for a decade before anyone could prove anything. Just like ubiquitous internet surveillance. And even when irrefutable proof surfaces, the very same people who staunchly said "that could never happen" will say "of course, how could you even be surprised?"
2 National security preventing your lawyer to ever see any evidence against you.
Both already being used in US.
Does your hard drive provide pointless-something-random functionality that RSA/NSA thought up? No? Well it's not allowed to be sold legally inside the United States, then. Please return with a properly functioning product.