Keystone "A provider of communications services cannot be held liable for the consequences of encrypted communications that pass though its system."

[E. Dean Tribble]

The Compuserver decision some months ago supported this indirectly:
Compuserver was held not liable for mail and postings on their system,
because they don't claim to read them.  I don't beleive Compuserve is
a common carrier, so the precedence supports the result you want.

dean