Martin R. Green writes:

>  There are some very sophisticated
techniques that are "very" destructive to the device under attack.  I
used to have a link to a site that described in detail some of the
methods these "service" companies use, but I seem to have lost it.
Maybe someone else out there will know the one I am talking about.

You're probably thinking of:

http://www.cl.cam.ac.uk/users/rja14/tamper.html

which has an excellent article on hacking microprocessor security.  I just
tried it and it's still there.  They also list this FTP site for a
postscript file, but I haven't tried it:

ftp.cl.cam.ac.uk/users/rja14/tamper.ps.gz

Dave, N9LTD