Smart dust, in the context of this idea, is very tiny pieces
of serialized matter that responds to radio waves with its
serial number. Sprinkle a little on your computer and if
someone steals it and it's later scanned the dust will
respond to the scan. This stuff is almost impossible to
remove
since it's very, very small. fairly sticky, and it only
takes one or two remaining particles to scan for a serial
number.
I have found a way to defeat it.
Make smart dust with already-issued serial numbers, plus a
few random ones. Millions of different serial numbers.
Now it's impossible to prove whether the result of a scan is
actually from dust originally placed or just happens to be
one of the millions of other particles.
Furthermore one can add to the plausible deniability by
placing it on other people's belongings. Now not only can it
not be confirmed that the dust belonged to the original
owner but it can't be confirmed that the confounding dust
was placed there deliberately.