I personally have at least one Truecrypt volume whose password I've forgotten. It contains a year or so's worth of journal entries, so I keep it around in case

I personally have at least one Truecrypt volume whose password I've forgotten. It contains a year or so's worth of journal entries, so I keep it around in case inspiration strikes, but so far I've had no luck opening it. Were I investigated for a crime, it's not implausible that the police might take my hard drive and come back saying something like "here's a list of encrypted volumes we found, open them", and in at least that one case, I simply cannot.