I still advocate electrified concertina wire.  There is no barricade that
discourages the insane, the stupid or the egomanical.  I have seen people
slip under and lean over the velvet covered ropes, step onto platforms,
reach around plexiglass, etc. they usually figure that because they mean
to admire and intend no harm they are therefore not harming what they
handle.  It is also a testiment to the beauty, energy, and spirit of our
forebearers that people want a literal connection to the past.  I imagine
that most of us got into the museum biz because we could feel that intense
attraction and resulting connection.