In the year 2000, my car was burglarized. The police knew who did it. They got his identity from the fingerprints. They told me that he would not likely face charges, because the police department did not have the resources to deal with "minor" crimes like auto burglary.
In the year 2005, someone stole a check from my mailbox, forged my signature on it, and deposited it into their checking account. I got a copy of the check, and sure enough, there was the name and signature of the miscreant. The police again told me that they didn't have the resources to pursue the criminal.
On the way home, I passed 5 cops writing traffic tickets. I lost a total of about $900 from those two crimes. I have lost more than that from the five traffic tickets I have received in my life.
The police write over 40 million traffic tickets a year in the US. The average officer writes $300,000 a year in traffic tickets. It is a $6 billion a year industry. The city of Atlanta has even admitted that police raises and pensions depend on how much revenue is brought in by traffic citations. So even though there may be no quota per se, you can bet that the police have a real motivation to write questionable tickets. The Atlanta police union admits to using traffic tickets to fund a raise for Atlanta cops.
Warning people of speed traps ahead has been ruled as protected speech, and has also been ruled as interfering with police business by the Seventh circuit. In that same decision, it also ruled that using traffic fines to generate revenue is legitimate police business, and interfering with that is a crime.
Florida, the state where I reside, makes $100 million a year from traffic tickets, and that doesn't include the amount collected by state and county government from their share of those 4 million traffic citations. Hillsboro county got another $36 million. St Petersburg, a city within that county, got another $500 thousand. Hillsboro is only one of 67 Florida counties. There are only 15 million adults in Florida, meaning that one in four Florida drivers get a ticket each year.
The police are revenue generators, and are being used to squash political groups. They no longer are here to protect and serve the public.