I think a lot of people aren't aware that open ended questions can be extremely rude, especially under certain circumstances. By asking an open ended question, you're assuming that the answerer has the time and inclination, not to mention information, to give you a decent answer. If you're interviewing someone, that's fine, it's expected.
If you call tech support and ask open ended questions, you'd better know what you're talking about, otherwise you're going to make a huge jerk of yourself. Not that many people seem to care anymore.
Example: Customer calls in and says his PS3 can't connect to the web, gives a DNS error. I immediately inform him that this is a known issue with the PS3, Sony has a fix, and to call them up. First off, had he checked his computer, he would've known it was working fine and there was no point in calling his ISP in the first place, so he's already under the table in dumb-points.
But then he has the gall to ask, "Well, what do I do if Sony can't fix it?"
I've already told him it's not my problem. I've already told him who to call. I've even go so far as to tell him, under no uncertain terms, that they have a fix. It couldn't be any clearer that I have nothing left to say on the matter, so an open ended question at this point is about as rude as you can get. He could've cussed at me and hung up and I would've been far less irritated.
Another good one. After troubleshooting a cable box, and the customer being very, very confused through the entire process, we get to the end of the line of what we can do over the phone and set up a trouble call.
And she asks, "What could cause this?"
For one thing, you couldn't figure out how to unplug your box, what makes you think you're going to understand what caused the problem? If you think you did something to cause it, how about you tell me? Why do you even think I know what caused it? I'm not out there fixing it. I'm on the phones, talking to you, and scheduling someone else to come fix it. I'd say that's pretty good odds that I have no clue, nor do I particularly care. I'm already passing it on to someone else; obviously I'm done here.
Even more irritating, sometimes, is open ended silence, or asking someone to hang on while you do something that has nothing to do with them.
Customer: I can't connect to my wireless router.
Me: Okay, it looks like you don't have wireless through us, so there's really nothing I can do with that. I would suggest you call the router manufacturer.
Customer: (silence)
Me: Is there anything else I can do for you?
Customer: Come on, you can't just help me out?
Me: No, it's not our equipment, therefore I can't do anything with it. Is there anything else *company* related that I can help you with?
Customer: (silence)
You can see that this is going nowhere, yet they persist. They're like little robots that don't know how to go around an obstacle so therefore they just ram it over and over again until they run out of battery power. Only the robot is funny.