In Casino, After Ginger is thrown out of the house by Ace, he is in bed watching the cameras from the eye in the sky from the Tangiers. How can he have that connected to his house from there with 70's technology?
Assuming they were using CCTV (most likely they were), CCTV can be broadcast and was invented in 1940's, so it was available in the 1970's.
Closed-circuit television (CCTV), also known as video surveillance, is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint, or mesh wireless links. Though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that may need monitoring such as banks, casinos, airports, military installations, and convenience stores. Videotelephony is seldom called "CCTV" but the use of video in distance education, where it is an important tool, is often so called.
Not too sure about CCTV distance (I know nothing about the technology), but I know he didn't live too far from the strip.
And if nothing else, it could have been delivered via cable
Beginning almost simultaneously in Arkansas, Oregon and Pennsylvania in 1948, cable originally brought distant over-the-air television signals from miles away to mountainous or geographically remote areas. In the 1960s and 1970s, cable TV expanded into bigger cities and major metro areas.
CCTV as a commercially available technology came into popular and initial use during the late 60s, early 70s. Most information about it refers to public use, government crime prevention programs, but a huge, mob run casino would have no problems getting access and paying for the technology. The same would be done for a private cable or data lines. T1 or better lines were available in the 70s as well.
The assumption of 70s technology being limited is really that the technology we are talking about were state-of-the-art systems with state-of-the-art prices, and limited to heavy pocket companies and governments. Consumers did not have access to it cheaply yet.