One of the security companies I worked for many years ago had a contract with Diebold(maker of ATM machines). The Diebold technicians would ask for me by name because they knew I'd protect them by setting up a perimeter and be prepared to defend it.
It didn't hurt that they knew I was a former Marine. Most times when I went out with the Diebold techs I brought my Mossberg 12 gauge with a pistol grip loaded with slugs and buckshot. I also carried a H&K USP40 back then
I went all over the Dallas area with them mostly at night to protect them. A few times we went to the Martin Luther King area of South Dallas and that was never fun. Fortunately I never had to shoot anyone. There were always bad elements around. Luckily the ATM techs were pretty good at quickly fixing problems and getting us out of those bad areas...