Most of the laws prohibiting scavenging are to prevent stealing private information, as far as I recall reading articles about it over the years. Once in awhile a scandal comes up where a celebrity's trash is ransacked and some kind of item or document gets publicized. They get really nasty about enforcing those laws in the wealthier neighborhoods. But I have picked up plenty of nice TVs in Beverly Hills alleys; including a mint-condition working CTC-5 Special table model out back of a house on Tower Road. (this was about 1984).
The moral of the story is be discreet, quick, and act dumb if caught. Being a tech-nerd, and offering a long detail of why a particular TV is a historically significant piece that needs rescuing can help too... It will show the officer that you are a harmless nut case into saving old TV sets, and you aren't after Jennifer Lopez' underwear nor Donald Trump's social security number
Charles