peb@PROCASE.COM writes:

...

Case 4: "I forgot."

This one seems to work for U.S. presidents.

My suspicion is (gee Mike, you're right! I *am* a lawyer!) that in such cases the court makes a judgement as to whether a particular claim of forgetfulness is credible. If the information in question is clearly critical to the life or livelihood of the person being subpoenaed (is there a legal term for "person being subpoenaed"?), the claim that the key has been forgotten is likely to be disbelieved. Of course, the court might say "Ok, gee, that's too bad. I guess it's OK then if we just hold these floppies under this head demagnetizer." -- Mike McNally