switching off a street light with a laser

has anyone managed to prove this theory?

apparently it is possible to point a laser pointer at the
light dependent resister or photo transister mounted on
the top of a street light to fool it into thinking its day time,
thus saving the local authority money, not burning up so much of the
Earths resorces therefore reducing carbon emissions.
unfortunately a regrettable side effect of this is that we all have
darker skies :-)

Simon