Dunno. I cannot predict the future. Can you? Somewhere someone is working on a fraud...
The people that see my plates daily are my neighbors, or people I drive past who get a blink of a chance to see my plates. My neighbors probably aren't going to try to fraud me. The people that see my cars daily are probably not working on frauds. The person I drive past on the street is probably not going to have the time or interest to fraud me. But a picture on the interwebs ... To get my license plate a thief would have to see me driving, or drive into my neighborhood, grab a camera, and take pictures.
"the few people" who see the ad on the interwebs are potentially hundreds of millions of people globally crafting schemes to gain information or steal property. Post your data online if you wish. I won't be doing that.
BTW, with a license plate you can get a Carfax or other reports and get a tremendous amount of personal information. With a bit of time and money you can learn the vehicle VIN#, owners ID, entire credit reports, family history, social security number, home address and location of the car, where the car is serviced, names and addresses of neighbors, etc. That's a lot of information that can otherwise be blocked by a simple concealment of a plate number...
Same is true with facial recognition technology. Sure, someone can snap my picture in public. But I'm not posting my face out there for the world to see and file in computer systems to ID me ...