I’ve gotten calls from cell phones where the ID says “Blocked Caller”. I don’t answer them, because I think its good practice to always screen calls from people you don’t know. I never find out who it is, though, because they hang up as soon as the machine comes on.
In my days with the utility, some of the field techs repairing electricity used to have company phones that did this to protect them, but I haven’t had any power outages in my area.
What other companies have access to and use “blocked caller” cell phones that leave no record with a telephone carrier?