Britain, holey stones were threaded and hung within the home
as a protective ornament. This home security system updates
that idea for the twenty-first century. Many burglaries are
opportunist crimes - about 10% are committed without using force
to gain entry, and are committed whilst the property is occupied.
consists of a a personal unit carried by the occupier, and a
number of sensor units, placed behind doors and on window sills
to monitor exterior movements - detection of which triggers
a warning back to the occupier's unit. This allows the householder
to take action, such as turning on the lights, which will alert
an opportunist thief to the fact that the property is occupied,
hopefully scaring him away.