It is very often the case that users will ask off-topic questions on SO. Mostly I see server-configuration questions, which are flagged, as this is technically not programming and the mods would say this should be asked on, say, Server Fault.
The major problem with this is that Server Fault is comparative tumbleweed neighbourhood, whereas SO is very busy and contains a LOT of users, many of which have the precise expertise sought for by the OP.
I see many off topic questions with a high number of upvotes, answers with high upvotes, and answers that are accepted before the question is closed. Clearly, the users of SO got a lot of mileage out of something that 'technically' shouldn't have been there.
Given the purpose of Stack Exchange is to find answers to problems and queries, is it not acceptable to allow questions to be asked in a community where expertise is so much broader than mere 'programming', as it often goes in hand with very regular server issues, and Server Fault just doesn't have the numbers to get the pleasant speed and efficacy of response seen on Stack Overflow.
This comes to mind because I'm currently waiting for an answer on SF, and I know that if I ninja'd my question on SO, I'd probably get the answer I need before it gets closed.