Practical "power thief"

I bought this branch connector because I nachrüstete a reversing camera in my age-old Fiesta. Instead cumbersome to separate cables or even to work with wire nuts, I got the tip from a friend, but so-called. To use electricity thieves. This term is probably used by professionals, some Google search brought me also the official and usable term: wire tap.
Those things have proven to be excellent. I was only a little skeptical, but at the low current of less than one ampere and at only 12V voltage, I think these things are not more dangerous than luster terminals.