Hello, there are a lot of black tax in my home country. These are located at railway stations, airports and larger cities, mostly with unobtrusive old cars. This is common and well known there. In this country I have never seen such a thing before, but have read on the Internet more often that there are also here in Germany. But I ask myself: how do these “black tax” look like? how do you recognize them? how does their daily business work? where are they represented everywhere? what tricks do they have in stock?