From: smb@research.att.com (Steven Bellovin)
Subject: Re: Clipper considered harmful
Distribution: inet
Organization: AT&T Bell Laboratories
Lines: 19

In article <1r24us$oeh@agate.berkeley.edu>, shirriff@sprite.berkeley.edu (Ken Shirriff) writes:
> Imagine archiving all pay-phone conversations, so if someone turns out
> to be a drug dealer, you can listen to all their past drug deals.  And
> archive calls to/from suspected Mafia members, potential terrorists,
> radicals, etc.  Imagine the convenience for the police of being able to
> get a warrant now and listening to all the calls the World Trade Center
> bombers made in the past year.
> 
> Since archiving would be such a powerful tool and so easy to do, why
> wouldn't it happen?

Apart from the storage and search requirements, because the evidence
is inadmissible:  wiretaps require a warrant.  And as soon as one
such case comes to light, all previous cases are likely to be discovered,
and thrown out.  There was an article in the NY Times a few months ago
about how many convictions in the state might be invalidated because
they relied on pen registers -- and the Court of Appeals ruled that
pen registers were equivalent to wiretaps, and hence required warrants
under New York law.
