The frog supposedly does not feel the slow increase of temperature until the water it sits in boils. In a similar vein people to not feel the loss of their freedoms when the observation and control instruments used on them are slowly more and more intrusive. The city of Los Angeles ratchets the screws up a few notches: Los Angeles is first in US to install subway body scanners

Los Angeles’ subway will become the first mass transit system in the U.S. to install body scanners that screen passengers for weapons and explosives, officials said Tuesday.
...
The machines scan for metallic and non-metallic objects on a person’s body, can detect suspicious items from 30 feet away and have the capability of scanning more than 2,000 passengers per hour.

The capacity to check 2,000 passengers per hour is way too small for a subway line which usually has between 20 and 30,000 passengers per hour. While the system is software supported it will still need a lot of paid staff to watch the screens and to bother all the people who might carry something 'suspicious'.  There will likely be dozens if not hundreds false alarms per day.
Pic: Thruvision - bigger

This is supposedly to prevent someone with an explosives belt or an automatic rifle from entering the subway with the intend to commit mass murder. But how often does that happen? Globally its probably once per decade with zero to a few dozen casualties in any such incident. The risk of an accident or fire is much higher. It is doubtful that the expenditure and operating costs are justifiable.

Such security theater has the effect and purpose to make people feel afraid. It also makes a few people very rich.

But we are told that it is good for us. And taking part in this nonsense it is of course completely "voluntary":

Signs will be posted at stations warning passengers they are subject to body scanner screening. The screening process is voluntary, Wiggins said, but customers who choose not to be screened won’t be able to ride on the subway.

The poor have little choice but to use the subway and to get 'voluntarily' screened. The rich though will not be bothered at all.