Deniability

[Robert J. Hansen]

On Tue, 22 Mar 2011 18:07:23 +0000, Jerome Baum <jerome at jeromebaum.com>
wrote:
> I'm saying what if Alice sends me incriminating messages? Like "burglary
> happens at 5am"? I can respond "I don't know what you're talking about",

Or just fail to respond.  If I received a message saying "the burglary
happens at 5:00am," I would be certain to have a rock-solid alibi for
5:00am, and I might even go to the police with it.

> but how does that help me? I could report her, but I might choose not to
> bother. (Hmm, is it a requirement if I don't think she's serious?)

The general rule in the United States is that no one has a duty to help
the police, but there are a lot of caveats.  There's a fine line between
"no duty to help the police" and "accomplice to a crime."

> See this  is exactly  the problem.  I agree it's  true but  it shouldn't
> be -- why is it incriminating that I care about my privacy?

In the United States there are several different thresholds for evidence. 
Simplified a lot, there are the kinds of evidence the police can use to
justify investigating you, and the kinds of evidence that can be offered in
court to convict you.

If the police have cause to investigate you and they see a counterforensic
tool on your hard drive, that can be justification for further
investigation -- in exactly the same way that if I was being investigated
for murder and they discovered I owned the exact kind of weapon that was
used in the killing, that fact could justify further investigation.

However, the fact you had a counterforensic tool, *by itself*, would
probably not rise to the level of something that would be admissible at
trial -- the same way that, if I was charged with stabbing someone to
death, the fact I own a shotgun would be inadmissible.  There would need to
be evidence of it being used unlawfully, like for instance, evidence
spoilation.

Again, this is extremely quick and dirty.  The Federal Rules of Evidence
are big, confusing, clunky, ungainly, and difficult to understand.  If
you're concerned about United States law regarding the admissibility of
evidence, you really need to consult with a lawyer.

> In  any case  I'd love  to see  that reference  to securities  fraud.  I
> haven't seen that one before.

http://downlode.org/Etext/alicebob.html