Continuing in the spirit of being nice (with all the recent pushes to be nicer to new users), I want to share something that I see frequently (I am working to build a list of examples, as per comments below). This is not limited to "new users", which of course has already been discussed to death.
A lot of times we see questions like "I want to connect my application to a database. How do I do this?" These are categorically "too broad" and by no means do they belong here. However, a lot of people (including myself) respond with snark and rudeness in addition to the appropriate close vote.
When I was in high school, I worked as a cook at Boston Market and Pizza Hut. I was cooking food, but by no means was I a chef. If I had asked a true chef, for whom cooking was an art, "I am cooking a pizza, how many pieces of pepperoni do I put on it and what is the precise oven temperature?" he would probably respond with something like "What? You don't understand cooking!" The question is almost incomprehensible to a chef who takes pride in his art form and is used to using instinct, taste, and experience to create; but the question is reasonable when one remembers that it is being asked by a person for whom cooking is just another job.
Similarly, when a person who is programming computers because it is a job asks a broad question without any apparent research effort being done, it could be because they genuinely (and validly) don't view their job as some sort of masterful art form that they are proud of, but rather as just another job (which they care about, it's just that they don't take the same approach), and they're simply looking for a solution that meets their requirements so they can move on. I think this may be a concept that isn't really aligned with the way many of the people who contribute answers here feel about programming.
These questions of course should be closed, but can we please try a little harder to consider where they are coming from and the mindset of the asker instead of being outright rude?
I had a little bit of trouble putting this into words but hopefully the spirit is coming across OK. If anybody here can improve this (especially the title, which I had difficulty with), please do.
Update in light of some answers and comments below:
I think it very easy to direct negativity towards the asker himself, but in some situations the root cause is the way the asker was trained to do his job. I realize that's way beyond anything we can or should be expected to address; but fundamental differences in the programming and training culture that an asker is a part of very much affects the attitude of the asker and how much value they place on finding answers on their own. I don't particularly agree with that culture, but the point is, an asker might not be a "lazy/stupid" person, it could just be how they were taught.
In light of this, another way to state the concerns above is: I suppose Stack Overflow has a heavy (and understandable) bias towards a certain kind of programming culture. However, it also seems that Stack Overflow has an apparent outward desire to be a global-friendly place to go for answers (see e.g. the tone of the recent Portuguese site creation blog post, which reflects a clear desire to be more inclusive). If SO outwardly stated that we only support the specific programming culture preferred by heavy answer contributors, then it would be easier to accept this kind of behavior as the norm; no false advertising. As it stands, it seems like a contradiction to an outward desire for a more tolerant attitude, and I think it will reflect positively on SO as a whole if we can try to at least show understanding (and again, these types of questions do not fit here, but it is not necessary to add a negative comment to the pool of information maintained here).
To openly not appreciate where others are coming from damages (slowly, yes, but also surely) Stack Overflow's efforts to maintain a positive global public image. As members of this community I think it is distinctly our responsibility to make sure that damage does not occur.
I believe this is what differentiates this issue from a basic "be nice to people because hurting feelings is bad" type of request. I do not and never will maintain that we need to be responsible for other people's feelings; but I do strongly maintain that we are responsible for Stack Overflow's overall culture and image.