If you consider police officers and judges to be that stupid, you don't even need that. You can simply say: "No, my hard drive isn't encrypted, I'm just collecting white noise."
The whole point of steganography is to not raise suspiciousness in the first place.
What if you were to use the noise (encrypted data on a hard drive) as a one time pad to send obviously innocent messages to your friend, messages you could produce the plaintext for on demand? With the right setup it would appear very innocent, if a little strange.
If you consider police officers and judges to be that stupid, you don't even need that. You can simply say: "No, my hard drive isn't encrypted, I'm just collecting white noise."
The whole point of steganography is to not raise suspiciousness in the first place.