      Just a question. 
      As a provider of a public BBS service - aren't you bound by law to gurantee
      intelligble access to the data of the users on the BBS, if police comes
      with sufficent authorisation ? I guessed this would be  a basic condition
      for such systems. (I did run a bbs some time ago, but that was in Switzerland)

The US doesn't yet have many laws covering BBSs - they're not common carriers,
they're not phone companies, they're just private machines or services
operated by businesses.  There's no obligation to keep records.
As Perry Metzger points out, if the police come with a search warrant,
you have to let them see what the warrant demands, if it exists,
and they generally can confiscate the equipment as "evidence"
(which is not Constitutionally valid, but we're only beginning to
develop court cases supporting us).  A court MAY be able to compel
you to tell them information you know, such as the encryption password
for the disk - there aren't any definitive cases yet, since it's a new
situation, and there probably aren't laws specifically covering it.
But the court can't force you to *know* the keys, and there are no
laws preventing you from allowing your users to have their own keys
for their own files without giving them to you.

Even in areas that do have established law, there is uncertainty.
There was a guy in Idaho a few years ago who had his business records
subpoenaed as evidence for taxes or some other business-restriction law,
so he gave the court the records.  Which were in Hebrew.
The US doesn't have laws forcing you to keep your records in English,
and these were the originals of the records.  HE didn't speak Hebrew,
and neither did anybody in the court organization.  Don't think they
were able to do much about it.

It might be illegal for your BBS to deny access to potential customers
based on race, religion, national origin, gender, or sexual preference;
it probably hasn't been tested in court, but it seems like a plausible
extension of anti-discrimination laws affecting other businesses.

