Ok, so I work at a local ISP doing tech support.
Customer: Hello, I just got my DSL modem yesterday and my son installed it for me.
Customer: Well, now my phone lines don't work. There's no dial tone, no nothing.
Me: (Warning flag goes off!!) Well, did you try unplugging the DSL modem after you installed it to see if it fixed your phone lines.
Her: No, we figured it would work because you said it would.
Me: Go over to your DSL router and tell me what's plugged in where.
She explains and the moron plugged the PHONE WIRE into the ETHERNET PORT! In other words, there's been a small steady pulse of electricity being thrown on her phone line for about a day and a half (Since she waited to call)
I explain this to her and she gets all pissed off! She starts yelling at me and telling me that she's going to sue if there's any permanent damage to her phone lines (Which there may or may not have been), she wants to speak to a supervisor, and she's going to sue our ass for screwing her up and she's never going to use us as her ISP ever again.
I calmly ask "Did you follow the instructions we sent you?" (By now my manager was on the line listening in as well because I had called him over for kicks)
As I figured, she said "No, my son installed it, he's a computer genius and it's pretty obvious where things should go"