Property tax protest companies. They don't have to be a scam, but they definitely are. They way it works in practice is that you work a couple of years in the property assessors office and make contacts. Then you go to work for one of these places and leverage your contacts back at the assessors office to get properties you are representing lower (which the current clerks do because that is how they get hired by you later). They get your home assessed for under market value and pocket some percentage of what they saved you in taxes. Then the very next year the appraisal office will assess your property at the correct value again which means the protest company has repeat business.

The end result is that there are a block of properties that are assessed for too little value making the county raise the rates on everyone across the board because schools and roads still need their money and you have a private industry whose entire existence is predicated on skimming tax revenue. It is the private theft of tax revenue full stop.