wrote:
An older case (this one from the 1970's) says that binoculars are not
widely in public use and are "sophisticated surveillance equipment."

There are binoculars and then there are binoculars. What can be seen in
a consumer grade 10x50 binocular, certainly an inexpensive common
binocular in the 1950s through the 1970s, is quite different from
30x100s available in the 1970s or even a pair of 100mm navy spotting
binoculars from the 1940s. It would helpful to have the case citation
(and a link to the case in Findlaw) so we can judge what size and type
of binocular were being considered.

On first impression, I would say that either in the 1970s or today, any
pair of binoculars mounted on a tripod would be considered infrequent
among the general public, but common among amateur astronomers. When
hand-held, the user is limited to low-magnification viewing due to the
"bouncing" of the hand-held image. Such binoculars (in the 8x35 to
10x50 class) present little risk to bystander's privacy.

But when mounted on a steady tripod, the viewer can use higher
magnification binoculars because the image is not bouncing around.
Bystander's privacy can be invaded from a distance.

Similarly, any small inexpensive telescope mounted on a tripod,
available either today or in the 1970s, can be used at much higher
magnifications than any binocular. Bystander's privacy is at a greater
risk when people abuse commonly available, inexpensive telescopes for
such a socially irresponsible form of terrestrial viewing.

In conclusion, any small inexpensive telescope of the 1970s could be
used to "surveil" persons to degree outstripping an expensive pair of
binoculars of the same era. It is a matter of magnification; not the
form of the telescope, e.g. monocular or binocular.

As to historical prices, reference copies of _Sky & Telescope_ are
available at your local library and could be used to reconstruct price
trends normalized to the current value of money.
Peace - Canopus56

??? A law student named "countchocula"?