There was no stealing involved, but I had a somewhat relevant experience a few months back. My grandmother was visiting me (in New York City) and accidentally left her pocketbook in a taxi that we took. After a long time of googling to try to figure out how to contact the cab company, I found out from a concierge at her hotel that there was a specific number you could dial to reach some sort of help line for the city (I think it was "311", but I'm not positive). I called the number and after listening to a recording for several minutes, I reached a point where I could speak a term and have it give me info on it. After saying "New York City cab company" or something like that, it gave me the option to give them a tax number so and they'd give me the number of the company. Luckily, I had paid for the cab with my credit card, and my bank app had the cab number in the transaction, so I was able to get the number for the company. After calling them, I got the number of the garage, who then gave me the cell number of the driver. I called him, and it turned out that he had heard us try to call the phone earlier (but couldn't get to the phone in time and couldn't unlock the phone to find the number to call us back at), so he went back to the spot where he had dropped us off to try and find us. He came back to meet us at the hotel, and we got the pocketbook back (and gave him a nice tip for his trouble).
From what I understand, cab companies acknowledge liability for their drivers, so they'd be much more inclined to take action against unscrupulous drivers. It seems plausible that people who want to use the pretense of driving others around to steal things from their passengers would be much less likely to want to driver for such a company, so I wouldn't be surprised if my experience with a driver willing to go out of their way to return items is much more common with taxis than Uber.
From what I understand, cab companies acknowledge liability for their drivers, so they'd be much more inclined to take action against unscrupulous drivers. It seems plausible that people who want to use the pretense of driving others around to steal things from their passengers would be much less likely to want to driver for such a company, so I wouldn't be surprised if my experience with a driver willing to go out of their way to return items is much more common with taxis than Uber.