In Illinois it’s a big scam. It is almost always for a right-turn-on-red which is legal. The argument is that you didn’t make a complete stop.
People who pay “tickets” issued by the red light camera companies are giving their money away. If the ticket isn’t issued by a city or municipality, then not paying it won’t affect your driving record. There is no way that the red light camera people can collect on it. Ignore the notices and if they send a collection agency after you send them a “drop dead” letter. (Be sure to send the “DD” letter registered mail with a return receipt request)
If more people fought this nonsense, these companies couldn’t stay in business.
I wonder if your advice, which sounds reasonable, would hold up in Texas? Our traffic laws may be a bit different, but this seems more a question of DEBT under the Uniform Commercial Code, than traffic law. Any Texas lawyers have an opinion?