In a city of millions, you can just move on like Typhoid Mary, leaving a trail of disaster in your wake and still make a decent living.
That’s not …. ENTIRELY true.
Even in a city of millions, references matter….or SHOULD matter, assuming people check them. Also, platforms exist where people can rate the quality of the services recieved, Ebay, Amazon, and most retail sites have rating systems for vendors, and of course there’s also the local Better Business Bureau.
And, as a final resort and if it comes to that, business fraud is frowned upon by the police, as long as a report is made.
So, although there is *some* anonymity in a large city, a screw job also requires a consumer who is so naive that they are willing to expend money on a “trust me” basis, without doing any checking of the vendor or service provider.
Which is the source of the old saying “A fool and his money are easily parted”, I assume.