I would call the company I’d targeted, ask for their computer room, make sure I was talking to a system administrator, and tell him, "This is [whatever fictitious name popped into my head at that moment], from DEC support. We’ve discovered a catastrophic bug in your version of RSTS/E. You could lose data." This is a very powerful social-engineering technique, because the fear of losing data is so great that most people won’t hesitate to cooperate.